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I've had a hard time grasping what's happening, but I think I finally get the picture. I thought it would be helpful to explain in simple terms what's going on. The situation is quite complicated with SegWit2x entering the picture so this is long but it should still be simple with minimal confusion due to interchanging terminology. If you like it please leave a comment to boost it so that other people can read it too.

Bitcoin blockchain quick overview
As most everyone knows bitcoin uses a blockchain, and all clients follow the same set of rules to ensure that the chain is valid. If someone breaks the rules, like sending a transaction without a fee that the rules require a fee for, then all clients will just ignore it. Changing these rules requires that people change their bitcoin software, which is called a hard fork. This obviously results in two chains since at least a little of the chain that uses the old rules will continue since not everyone will want change their software. The old chain can get stalled quite badly since it takes a long series of blocks for the difficulty to adjust and if nearly all of the mining power switches away from the old chain then the old chain gets stalled.

Definitions:

• User activated soft fork (UASF): When just the miners change something in the blockchain that doesn't break the rules. Regular clients don't have to change software. 51% or more miners enforce a new rule and then the remaining 49% have to switch to the new mining software else their blocks won't be accepted anymore and they can't make money.

• SegWit (Segregated Witness) BIP141: A soft fork method of increasing the blockchain capacity by about 4 by changing how transaction signatures are stored without changing the 1MB block size limit. Already adopted by Litecoin.

• SegWit2x: An eventual hard fork that increases the block size limit to 2MB, in addition to having SegWit features. It enables itself on July 21st and when 80% of the SegWit signal is present. Initially it is a soft fork that will compete with SegWit / BIP148. By design, after about 3 months it will increase the block size which will be the hard fork, and everybody not just miners will be affected.

• Bitcoin XT, Bitcoin Classic and Bitcoin Unlimited: Other proposed methods of increasing the block size 1MB limit.

• SegWit signal (bit 1): A mark left in a block meant to signal that that miner supports SegWit. Introduced with BIP 8. It exists purely for statistics reporting for future client decision making.

• BIP8: A method of activating the SegWit UASF where miners switch to SegWit after the SegWit signal reaches 95%. It Expires in November 2017.

• BIP9: A version of BIP 8 that does not expire.

• BIP148: A method of pushing all miners to adopt SegWit clients (or at least signal the SegWit flag) by only needing 51% to go along with it. This is like a 51% attack. It triggers on August 1st and BIP 148 miners will not accept blocks that do not have the SegWit flag present. This is necessary because the SegWit signal isn't reliably reaching the 95% needed for BIP 8/9. I think that once SegWit is activated on the chain BIP 148 is not needed and disables itself.

• BIP 149: A feature that allows miners to turn on SegWit when they want to rather than have it happen automatically based on the software's hard coded trigger. This may be the same as SegSignal.

• NYA string: A marker left in blocks mined by SegWit2x software, potentially used by SegWit2x miners to identify their blocks and reject non SegWit2x mined blocks thereby creating a soft fork. This is the first half of SegWit2x adoption. Correction: It's the same concept as only allowing mining of SegWit compliant blocks once SegWit goes live. I'm still unclear about how NYA / Bit 4 are to be used concerning fork enforcement.

• BIP91 or Bit 4: Correction: It's the standardized version of NYA, put in to the proper version field. It creates the unknown blocks being mined warning. It's the same as NYA but newer clients do this in addition to NYA. It may be an additional activation method of SegWit2x miners or fork enforcement method of SegWit2x when it activates.

• btc1: The name of the client miners are using to push SegWit2x.

• replay: An issue that can cause coins for the other chain (other coins) to be spent without your knowledge along with the coins that you intend to spend from the blockchain that you're using if there is a split in the blockchain. A specialized client that's aware of the split is needed to avoid this.

• ASICBoost: A patented mining performance optimization of up to 30% that can be done overtly such that such minded blocks are publically visible, or covertly. Covertly mined blocks may hide from the patent but are not compatible with SegWit, creating resistance to SegWit from some miners.

• Bitcoin Cash (BCC): This in an altcoin that's trying to take advantage of the confusion surrounding August 1st to start their own fork. They're just trying to make their own fork of Bitcoin that will be different from both SegWit2x, and classic Bitcoin (which will come in to existance after the SegWit2x hard fork around November).

The future Bitcoin scailing issues explained
To get to the point, competing segwit and segwit2x are being planned for the Bitcoin network. This allows the Bitcoin network to scale to a larger number of transactions by allowing the Blockchain to grow at a faster rate, which is currently limited by fees, and a hard 1MB per block limit which limits the blockchain size to a bit over 50GB per year. It will also raise the system requirements for running a full node, and more people running full nodes is important for the security in distribution of the Bitcoin network. Segwit2x is a hard fork after an initial soft fork. Your bitcoin software will have to be changed if you want to go along with it. Segwit is a soft fork. But this is the second step in the plan. Both BIP148 leading to SegWit and SegWit2x's initial soft fork leading to a hard fork are two step strategies.

Note: SegWit2x is now adopted in the mining world. The BIP148 related things are probably no longer an issue

BIP148 and August 1st soft chain forking explained
The first step involves BIP148 which operates like a 51% attack on August 1st and it involves the SegWit support flag in blocks. The whole purpose of BIP148 is to use 51% of miners to force >95% of miners to use SegWit clients so that SegWit can activate. Miners and mining pools are encouraged to upgrade to a special client that supports BIP148 & SegWit that puts flags in mined blocks which signal SegWit support. All SegWit supporting miners leave the SegWit flag be they BIP148 or older BIP8/9. Non BIP148 clients ignore this flag. On August 1st 2017 this flag will become mandatory for users of the BIP148 mining clients. These miners will no longer accept blocks mined by non BIP148 clients. This a strategy to force the remaining minority of miners to switch to BIP148 clients. If a majority of miners are BIP148, then all of the blocks mined by non BIP148 clients will not be accepted by the BIP148 mining majory and there will be zero profit in mining, so they will switch over to BIP148 or give it up. The BIP148 minority situation: If a minority of miners adopt BIP148 miners, then there will be two chains, with BIP148 miners only accepting previous blocks mined by other BIP148 clients, and the non BIP148 clients choosing the longer chain which isn't BIP148. If this happens eventually the BIP148 miners will give up and switch back to the non BIP148 client.

SegWit2x enters the picture creating another possible fork situation
There exists another problem. BIP148 only exists to speed up the adoption of SegWit by forcing all miners to mine with SegWit clients. If SegWit is enabled before August 1st because 95% or more BIP8/9/148 clients are mining, then BIP 148 and August 1st is no longer a thing since its purpose has occured already. The problem is that the BIP148 fork also won't happen if SegWit2x (in initial soft fork mode) becomes the dominant chain, since SegWit2x also enables SegWit. So the soft forked chain won't be BIP148 and original non BIP148, it could be SegWit2x in a minority competing non SegWit2x (normal and BIP8/9/148) clients, just like BIP148 could be a minority competing with non BIP148.

The full impact of SegWit2x successfully soft forking leading to the hard fork
The second step happens after successful adoption of the SegWit in the mining community. When SegWit is activated, it could have happened because 95% SegWit flag was reached, or because August 1st came and BIP148 forced the 95% needed for SegWit adoption, or because July 21st and 80% of the SegWit2x flag or flags was or were present and SegWit2x activated, which also activates regular SegWit. SegWit2x is the big question here and it can activate at any time after the 21st. It's actually a much bigger deal than the non SegWit2x related August 1st issue. The initial adoption of SegWit2x isn't the problem since it's essentially the same as SegWit. The problem is that this SegWit2x mining software eventually enforces a hard fork. If SegWit2x wins the soft fork, then after about 3 months that software will enforce a hard fork and allow 2MB blocks. All users of bitcoin will have to change their software or continue using the classic wallet, but the classic wallet will be stalled and it will take ages to confirm a transaction because most of the mining power left and because it takes a long time for difficulty to adjust back down to 10 minute blocks. edit: Maybe I didn't make it clear, but if you continue to use the classic wallet, in addition to the initial slowness, you'll be on a different forked network that's completely separate from the new SegWit2x one. Also, with the hash power lacking on the classic network, it will be easy for interests behind SegWit2x to do a 51% attack and stall the classic network and discourage anyone trying to stick with classic Bitcoins. edit: It looks like we may be getting SegWit2x, and if it sticks then we'll get a hard fork around October/November which may be here to stay as two different networks, so you'll want to have BTC in your wallet before the hard fork date so that your coins will exist on both sides of the split, with you having both original and SegWit2x coins.

There is also a 336 block grace period after SegWit2x activates (after the 80% tigger) before the SegWit portion of it activates. So BIP148 could still activate on August 1st if SegWit2x happens to still be in the grace period phase. So that could lead to a soft fork between SegWit2x and BIP148. If both BIP148 and SegWit2x somehow had shorter chains than the classic miners' chain then a 3 way fork would result, but I don't see how that could happen. The SegWit2x chain should come out as the winner since it already has around 80% of the hash power behind it. I don't see why this is a big deal since there should be a clear winner and only BIP148 miners or clients who downloaded the special BIP148 client would get stuck on the BIP148 chain.

Forked blockchains and the potential for a stalled or split network
If BIP148 fails and is a minoriy after August 1st, or if SegWit2x fails is a minority after it activates, then the possibility of having the blockchain soft forked two ways exists! A three way fork is not possible since BIP148 disables itself when SegWit activates, and  if SegWit2x wins the soft fork it will enable SegWit which will disable BIP148. All these complicated things have lead up to this simple fork situation that everyone is talking about! It's unlikely but if two chains exist with one not becoming the clear winner then it'll cause havoc to all exchanges and regular wallet users as they won't know what coins they are spending or receiving until the situation is cleared up. It could be between BIP148 and classic or between SegWit2x and everyone else.

Multiple coins could temporarily exist after a fork
Another thing worth mentioning is that if the August 1st BIP148 adoption fails, or if SegWit2x adoption fails and two chains result, people with modified clients or who are otherwise able to select which blockchain to participate in will have two sets of coins to spend, and will be able to choose which ones to spend. People could potentially be cheated by receiving coins on one chain which ends up dying and having those coins disappear, while the sender still has the same coins in the other chain. During the split even if BIP148 wins the old chain will likely keep going for a few blocks so don't do any transactions for the first hour or two after the August 1st trigger!

I hope that helps make things easier to understand! Please let me know about any mistakes and please comment!

Here are some sites that are tracking the progress or the markers that the particular miners leave in the blockchain for the potential changes:
This ones shows a 100 block average and a 1000 block average. You can see BIP 91 (Bit 4) adoption really surging in the last few days (2017-7-18) due to the large 1000 block vs 100 block difference: https://www.xbt.eu/
This site shows a regular graph based on 2016 blocks: https://coin.dance/blocks/proposals
Note that the SegWit2x (btc1) client does not necessarily signal SegWit (Bit 1) until SegWit2x activates with its own trigger. That's why SegWit shows lower on the graph than SegWit2x (NYA & BIP91).

Sources:
http://www.investopedia.com/terms/s/segwit-segregated-witness.asp
https://bitcoinmagazine.com/articles/bip-148-and-bip-149-two-uasfs-activate-segwit/
http://www.coindesk.com/explainer-what-is-segwit2x-and-what-does-it-mean-for-bitcoin/
https://medium.com/@jimmysong/uasf-bip148-scenarios-and-game-theory-9530336d953e
https://medium.com/@jimmysong/segwit2x-what-you-need-to-know-b747e6326266
https://www.reddit.com/r/btc/comments/6i74o4/eli5_why_does_segwit2x_activate_segwit/
https://bitcointalk.org/index.php?topic=2027513.0


There is no restriction on copying or publishing what I wrote here.
Edit 2017-7-17: added and corrected things concerning the difference between segwit and segwit2x, BIP 8/9, added sources, and added definitions.

Sorry, but don't you mean August 1st, not April 1st?

Segwit is a scam.  Do some research. Check r/btc

Thanks. I fixed that and I added a lot of new information. I've learned a lot about what's going on. I read that China has over 80% of mining and they're pushing SegWit2x but I didn't include that information since I don't know how to verify if it's accurate.

For a moment believe its a real news, but then What will 80% of the Chinese miner will benefit from this hard fork, I am  fail to understand this  :(
For the article, it is excellent, summing up all the information a single page. Great information  compiled by OP..

Okay thanks I believe all the wirting April instead of August mistakes are finally fixed.

Unorganized? Do you have a source that's better organized and gives people a fundamental understanding of what's going on? I couldn't find anything out there in one place that explained all these things.

This here! Support http://www.bitcoinabc.org Satoshi's true bitcoin.

Roger Ver/Jihad/Craig Wright sockpuppets. Reddit is a shithole period. There will be no hardfork because all hardfork proposals are trash. Going into the forked chain will result in loss of purchasing power as the forked token crashes into the ground. Do not support any hardforked token unless you want to lose money.

In other words, you have nothing to add to this discussion. Bye brainwashed Core worshiper. Can't wait until you fools will be worshiping an altcoin or be out of bitcoins way entirely.

Thanks for explanation but notice antminers will be useles.

Only for the useless Core altcoin. They will still be working great for actual Bitcoin!

Segwit not really well tested
Exchangers will accept it only like fork of BITCOIN of 2014 (CLASSIC)
-----------
Exchangers Position:
https://poloniex.com/press-releases/2017.03.17-Hard-Fork/
---------
Have all answers about Aug 1.
Easy topic:
https://bitcointalk.org/index.php?topic=2007635.msg19988238#msg19988238
Complex topic:
https://bitcointalk.org/index.php?topic=2018878.msg20119234#msg20119234
----------
Anyway smart people will make smart decision, no one want kill BITCOIN

SegWit (not SegWit2x) is a soft fork that only affects miners. Well it potentially affects everyone but only miners need to be involved in it. You can't choose to not accept it unless you modify your client, and if you do you'll be on a chain thet won't be mined unless some miners have done the same modification and are mining a non segwit chain.

Not realy:
Example:
In block N have segwit transaction from A->B .
In block N+1 have normal transaction from B->C .
Block N+1 rejected by BITCOIN of 2014 (CLASSIC) because B have zero balance.

Wouldn't that then make SegWit a hard fork if clients do not accept it? Are you referring to miners or regular wallet users in this example?

Exchangers will make decision.
Poliniex.com position:
https://poloniex.com/press-releases/2017.03.17-Hard-Fork/

Dear god, you can't even post a useful guide to others without it being hijacked by trolls trying to push their own agendas down your throats.

This discussion soon will become a battlefield of hate, like in every other case when different scaling solutions are being discussed.
Can we just agree that there is not 100% perfect scaling upgrade? There will be always people hating it because... reasons.
We will have SegWit activated whether you like it or not as some kind of scaling is needed ASAP. Deal with it and don't be bitter.

SegWit is ok (expect it not well tested), but "soft fork" imposible.

Checked r/btc.  The claims that it's a scam look something like the one in this thread (https://www.reddit.com/r/btc/comments/6nsd0c/the_6_months_to_2mb_hf_activation_of_segwit2x_is/).
Your argument here very much resembles the argument by assertion section on Rational Wiki:
Unfortunately your logic relies on the "we have proven this many, many times" kind of logic without making it clear where these points actually are.

---

Only SegWitx2 is poorly tested and new.  SegWit itself has been around for ages, and is already implemented on Litecoin.

I don't know have Litecoin SegWit transactions now or it just option.
With litecoin all exchangers installed new software without questions.

But it not gonna happen with BITCOIN:
https://poloniex.com/press-releases/2017.03.17-Hard-Fork/

Also about 15% miners support BITCOIN 2014 (CLASSIC):
https://blockchain.info/charts/bitcoin-unlimited-share
https://blockchain.info/charts/bip-9-segwit

It seems like you're making up stuff xbiv2. You didn't answer my question about SegWit being a hard fork regarding your example of a transaction where N is SegWit N+1 is not and then N+1 is rejected because the previous transaction it is based on was not accepted. Or maybe you're on to something I don't know.

Just send RAW not segwit transaction in block N+1 from B->C.
New segwit software (of miners) will accept it, BITCOIN of 2014 (CLASSIC) will reject.
It can do anyone who own BTC to pay transactions fee.

okay so the bitcoin i currently hold in bitpanda and in blockchain wallet... should i just leave them there? will my coins just become what ever the outcome is?

Should i transfer my bitcoins from those online wallets to a local core wallet on my computer? if so how do i download the wallet for the 'new' bitcoin? how will my coins be duplicated to the new coin??

Will my mining rigs currently mining dash and eth and other alt coins be affected?

gaddd i hate all this forking shit! haha

@xbiv2
The best I can understand what you're saying is that original non segwit miners won't process any SegWit transactions. And possibly any normal transactions that are based on BTC that came from a SegWit transaction won't be processed either since they don't recognize the source BTC as being valid.

I don't understand the second part though since if non mining clients accept the BTC as valid which they should since this is supposed to be a soft fork then the non SegWit mining clients should accept it as valid too. Of course this situation would only happen if for some reason the SegWit miners fell below 50% and a longer non SegWit chain formed off of the SegWit chain.

Earlier I mentioned what would possibly happen if some miners made special clients that refused to mine the SegWit chain, but this doesn't apply because if that happened those special miners would start before SegWit enabled block and no SegWit transactions would exist on that chain at all.

This is a problem in an in progress soft fork situation where a clear winner hasn't won yet, in this case leave them in until the situation is resolved. The other situation is a hard fork that results in two chains. You want your coins in your own wallet so you can have coins on both sides of the fork. Your eWallet will end up on one side or the other and not give you two sets of coins. It should be the better side but still it's only one side.

Bitcoin-core 2014 and wait until everything calms down and clears up.
For Bitcoin-core need SSD 240GB or it will work slow.

All SegWit chain will be regected by classic (2014) miners and clients.

Agreed. I knew it was complicated but didn't realise it was that complicated.

@Mad7Scientist
Good job gathering all of this information. This is easier to read and more condensed then the coverage provided by most of the bitcoin news blogs.

The old client will still work but if the network moves with the hard fork no one will accept transactions from the old folk. You will have to update your client in order to send or receive transaction that the rest of the network accepts.

Even as an old member of the community this terms I understand but in all honesty I don't know what will the affect of it when it comes to Bitcoin's price. We need a definite conclusion on the matter we don't need to understand the meaning of those terms as everything is available throughout the web and this site. We need a conclusion or an answer if Bitcoin will still grow after August 1 or will it start to fall. Other than that I might just need to start researching more about that matter. And can anyone please guide us on what will Bitcoin's future be?

https://pastebin.com/ZUxTmR99

Yes I thought that was implied but I edited that information in the post in case anyone doesn't understand that using the classic non SegWit2x network (after the hard fork) will be a completely different network with completely separate coins.

edit: Another thing is that I can't seem to figure out what triggers SegWit2x. Someone said that it triggers at 80% of the bit 4 flag, but someone else said that there are multiple triggers for it. Right now Bit 4 is signaling around 50% for SegWit2x so if it activated now it would do a soft fork and have the potential of winning the soft fork.

It's ok Roger, now ABC can soon join the club of defeated hardfork attempts along with XT, Classic, Unlimited and so on. It's pretty funny how they keep trying to come up with all these scams and they all end up on the dumpster.

... as long as the fight ended with SW2x - I don't care   ;D

People still seem to be confusing SegWit2x with SegWit and callign SegWit a hard fork. Time to read up, and point out flaws that are still in my OP! There are still likely mistakes in my post, especially concerning Bit 4 and the difference between that and the NYA string.
Here are some sites that are tracking the progress of the proposed changes:
This ones shows a 100 block average and a 1000 block average. You can see BIP 91 (Bit 4) adoption really surging in the last few days due to the lange 1000 block vs 100 block difference: https://www.xbt.eu/
This site shows a regular graph based on 2016 blocks: https://coin.dance/blocks/proposals

What I'm wondering is are the SegWit2x supporters not putting the SegWit flag in the blockchain since there is a higher number of NYA blocks than SegWit (Bit 1). Are they trying to cause BIP148 to make a fork on August 1st to divide the existing mining so that SegWit2x can be deployed and have a better chance of winning the soft fork? It's confusing but if BIP148 enforces SegWit on a shorter chain creating a fork then the longer chain will have a lower mining power due to the lack of BIP148 miners and then SegWit2x can be activated on top of that chain?

here is what i know from reading stackexchange and the developers doc:
the process of soft forking is first "signalling your support" then if the support reached a threshold, you soft fork and the remaining hashrate upgrades too.

now for that signalling part, the official method is to use the variable in the block header called Version. those numbers that you see on block explorers as version are these (little endian binaries). there are room for about 29 proposals. right now we are using about 4 or 5 of them.
here is the list:
0x20000000 Nothing
0x20000002 SegWit Bit 1
the above is the only official Bit that exists: https://github.com/bitcoin/bips/blob/master/bip-0009/assignments.mediawiki

because of that, so far miners have been using coinbase text to signal readiness or you can think of it as a promise to support when the time comes or like voting. they can add anything there, so they support multiple at times.
then as btc1 or SegWit2x merged BIP91 it also introduced the bit 4 for activating SegWit so they started using that.
0x20000010 SegWit2x : Bit 4
there have been others but i don't know what they are and can not find anything on them.

with bits the same as coinbase string, you can still support more than 1 proposal. it is simply done by adding the bits together. that is:
0x20000012 SegWit and SegWit2x : Bit 1 and Bit 4

Thanks for all that information Pooya87.

The next thing I need to add is the replay issue. If Bitcoin splits in to two chains there will be a new coin and a classic coin, but if you spend coins on a wallet that is not prepared for handling both coins it may spend the coins from the other currency or the other side of the split so you end up losing coins without realizing it.

*bump*

In looks like SegWit2x is coming. I think this post is important! It's not really right that some threads where people are arguing about some silly thing stay on the front page or a new post that consists of something like "Will bitcoin die" with no explanation of what's going on is what people see on the front page of the forum.

I think bitcoins splitting does not change anything for our company. We use bitcoins to process all of our platform orders. We get paid in minutes and cash out the same day to our bank. For 2H2 its a powerful processor.. beats credit cards all day long.  :D :D :D :D

What do you think about change bitcoin to another cryptocurrency on 1 august or before?

It's not changing in to a new coin (hard fork) until after SegWit2x activates and the scheduled hard fork happens around October.

Okcoin also releases hes position:
https://www.okcoin.com/t-423.html
More about it in my signature:

My wrong,antminer useless minus % off patch bitmain in orginal btc.

This is going to be very very important:


So at least one of the exchanges are going to support all the chains.

Time to add some information about BCC (Bitcoin Cash).

Great topic. I understand more whats happening in the blockchain, you compiled all the news to make it short.

So august 1 should be ignored now? Segwit is 100% now.

Why you ignore BITCOIN-CORE OF 2014 ?

https://bitcointalk.org/index.php?topic=2044085.0

RE: BITCOIN CORE OF 2014
I know that SegWit support has been added in 0.13 but that shouldn't really affect anyone who isn't mining. If you're mining you have to have it else your blocks will be rejected but since it's a soft fork it's not supposed to affect the amount of coins in your wallet or your ability to send and receive on any version of the client.

Yes I think it can be ignored. BIP148 defunct now. But I think at least BCC will hard fork off on the 1st of April so if you want to sail in that ship you need your coins in your wallet now to have your coins with them too.

It's nice when people reply then this thread goes to the top for another 5 minutes and more people get to see it.

This is a pretty fantastic resource you made here OP! If you don't mind, I'd like to use it as a resource in adding to and updating some of my definitions in Decryptionary.com (http://Decryptionary.com)?

Sure go ahead.