What is the Blockchain?

[baconbit]

I understand when you start up the bitcoin app, it must download the blockchain which is why it is laggy at first.  What exactly is this blockchain?

All help is greatly appreciated!

[1714000743]

1714000743

[Lord F(r)og]

I understand when you start up the bitcoin app, it must download the blockchain which is why it is laggy at first.  What exactly is this blockchain?

All help is greatly appreciated!

http://en.wikipedia.org/wiki/Bitcoin#Block-chain_and_confirmations

https://bitcointalk.org/index.php?topic=15918.0

[CoinExchanger]

I understand when you start up the bitcoin app, it must download the blockchain which is why it is laggy at first.  What exactly is this blockchain?

All help is greatly appreciated!

The blockchain is bitcoin. It is the torrent file we all share. it is the record keeper. It is the solution and the reason why bitcoin is what it is.

If you need coins visit, www.coinexchanger.com

[Shawshank]

I understand when you start up the bitcoin app, it must download the blockchain which is why it is laggy at first.  What exactly is this blockchain?

All help is greatly appreciated!

All transactions that have occurred since the creation of Bitcoin are stored in the block chain. A copy of the block chain gets downloaded automatically to your system once you start your Bitcoin client. Currently, 149520 blocks have been created, so it may take a while to download all of them.

It is expected that future versions of Bitcoin will address this issue, so that Bitcoin scales better, even for low memory, low storage devices.

[RodeoX]

Because there is no central authority or server for bitcoin, each client is a peer node on the network and maintains a record of all transactions. The blockchain is that record. (It gets more complicated, but this is an important function of the chain.)

[factotumjack]

All transactions that have occurred since the creation of Bitcoin are stored in the block chain. A copy of the block chain gets downloaded automatically to your system once you start your Bitcoin client. Currently, 149520 blocks have been created, so it may take a while to download all of them.

It is expected that future versions of Bitcoin will address this issue, so that Bitcoin scales better, even for low memory, low storage devices.

That's one block for every 10 minutes since Bitcoin started right? That would make sense, it implies about 2.85 years worth of blocks.

Is each block in the chain the same size and overheard, or does that increase with the number of transactions that happened in that block?  I can see that becoming a major hassle given that blocks in the chain never retire. If it becomes a problem, I would consider chipping in for a bounty for a solution.

[odysseus654]

No, blocks are different sizes depending on the number and complexity of the transactions contained within it.  I believe there is an upper limit of 1MB on a single block, although I don't believe it's ever gotten that high.  There's also a bunch of "suggestions" as to which transactions to choose to include in a block.  It is the mining pool's (or sole miner's) sole decision as to which transactions to include in a block, so there may be many waiting transactions when a new block is generated that only contains a single payment to the pool/miner.  This is when transaction fees enter into play in an attempt to "bribe" the pool/miner to accept transactions.

You can use http://blockexplorer.com to explore the blockchain, on each block you can examine which ones came before and after, which transactions were a part of the block, and the size of the block (which is usually less than a dozen kb)

[factotumjack]

Excellent, thank you!

That explains why the first 100,000 blocks were downloaded before I'd even noticed, and why it's chugging ever so slowly now that I'm nearly caught up.

[inki]

Enlightening. Thanks guys.

[robocop]

I think the bitcoin wiki is very useful for a newbee.
It helps me to understand the bitcoin.

[finway]

The whole database.