How does a bitcoin look like?

[Valnurat]

When you mine, how do I know that I found a Bitcoin?
I see a lot of accept and then a number/text and diff something, but what is that? Is that Bitcoin?
Sorry for n00b question.

Br

[ranochigo]

You'll probably see a whole lot of Accepts but those are merely hashes which meets the predefined difficulty that is dictated by the client. If you're mining with a pool, having a hash above the current difficulty won't net you the whole block rewards but would be proportional to your contributions to the pool.

The current difficulty is at 23,137,439,666,472 so you'll need to find something at that difficulty for it to be a potentially valid block. If it is anything less than that, you'll be awarded proportionally by the pool or if you're solo mining, net you nothing.

[BlackHatCoiner]

When you mine, how do I know that I found a Bitcoin?

If you're talking about a single Bitcoin, you never "find it out". At least, not like a piece of gold from the underground. In Bitcoin, you're rewarded for helping the network to extend the chain with all the transactions ever made. To do that, computational power is required.

Why is it required?

Because nodes are programmed in a way to accept the chain with the most effort dedicated. This way, if the majority of the computational power is owned by nodes that want to protect the network, then they'll outpace any attackers that will try to change past blocks.

What exactly am I calculating?

SHA256 hashes. If you don't know what is a hash function at all, think it as a function that can be used to map data of arbitrary size to fixed-size values. For example if you hash the text "I'm BlackHatCoiner and I don't own any altcoins." then you'll get this hash result:

Code:

6139b7e6357e2c1a89fdbed42dfd9b867c5c7bb3be0384d59363c57c9a2d0ad0

Each time you hash a different message, you get a new unique SHA-256 result, the so-called message digest. [Try it!]. In order to mine a new block (that will reward you with 6.25 bitcoins at the moment), you have to perform SHA256 to the block header. A block header is consisted of some important fields that define your block. There's a field called "nonce" which is just a number. By changing this number you'll get a completely different hash each time.

In order to successfully mine a block, you'll have to find a message containing the block's structure in which once you perform SHA256 to it, it'll return you a hash below a certain target. That target is calculated by the network's effort and it changes every 2016 blocks to ensure that no matter the total miners, each block will be solved every 10 minutes on average.

For example: If target is equal with:

Code:

00000000ffffffffffffffffffffffffffffffffffffffffffffffffffffffff

You'll have to find a hash that is not greater than that.

Code:

After many many tries...
45a9c90dbd4632398396d550dbf383a428d6920ba5dddf356d895c6baf928bb9 <- Nope.
491a0a72eb51cb35a1181adafe8ea04474b414f2599b0ed26a7f019fa4f1cc81 <- Nah.
ec43dd411ce7ac6707a502a7c80b61cf8fc4cd66015f03a5c127ec8f28e5bdaf <- No.
b53c6386c451653cf740285cd65eca05b41c5da889fafaa06e4dc1dabfb53826 <- Neither.
00000000827d29aff6dd1f65c772885502960a7416957e5a00dfcff8a4374bdc <- Bingo!

So once you find that hash you can broadcast it to the network along with your block's information and the nodes will accept it if it's valid. You understand that the faster you can calculate these hashes, the more possibilities you have to find such hash. It's a competition. If you can calculate ~100k hashes per second, then you have no chance against a man who owns machines that can generate the 1000x.

[Ibrahim60]

When you mine, how do I know that I found a Bitcoin?
I see a lot of accept and then a number/text and diff something, but what is that? Is that Bitcoin?
Sorry for n00b question.

Br

Bitcoin is a virtual coin, for this reason you can't feel this coin by your hand or can't touch it. When you get one or more bitcoin then you can see it in your bitcoin wallet. Bitcoin is a Crypto currency not a text. You can see number of how much bitcoin have you in wallet. Without any reason like contest, buying btc, getting payment; you never get bitcoin in your wallet.

[LoyceV]

When you mine, how do I know that I found a Bitcoin?

It appears in your wallet
This (old) screenshot shows what you're looking for:

(source)

[khaled0111]

I see a lot of accept and then a number/text and diff something, but what is that? Is that Bitcoin?

Those numbers tell you how many shares you have. Accepted share are what you are going to be paid for from your mining pool. More accepted shares = higher reward.
You probably will see some rejected shares and that's totally fine. You don't get paid for rejected share, the lower the better.
Whenever the mining pool solves a block, it will split the reward between miners who contributed to the work according to their accepted shares.

[bL4nkcode]

When you mine, how do I know that I found a Bitcoin?
I see a lot of accept and then a number/text and diff something, but what is that? Is that Bitcoin?
Sorry for n00b question.

Br

It shows on your wallet. Those numbers and text are only hashes of the transaction or transaction id.

You can't see, feel or touch bitcoin. It's digital after all.

Bit surprised asking from a full member, feels like you're a brand new account asking such question.

[JerryKin]

This looks like a question someone who knows nothing about digital currency would ask.

This question indicates ones shallowness in the understanding of what crypto currency is in it's entirety.

 I mean how do you understand that Bitcoin is decentralised if you don't understand how that it is virtual and can't be seen or held physically.   

Its just like asking what colour is your breathe.