What is blockchain and how does it relate to bitcoin?
bttt....I'd like to read any answers to that
Blockchain is the underlying technology for bitcoin. It is easier if you think of block chain as an old passbook or ledger that has some additional protections. In this analogy, each block is a VERIFIABLE (cant be faked) and NON-REPUTABLE (cant be denied) entry on the book. To follow the analogy, consider a passbook or ledger where every entry has a public notary stamp.
These two capabilities are protected by cryptographic hash functions which secure the transaction. It is not possible to alter the transaction as the each transaction can be verified by running the hash program. If the hash returns a different value, then the block and possibly the whole chain is broken. The hash functions are very mathematically difficult and are one way hashes. Meaning that there is an easy way to calculate the hash but there is no easy way to go from the hash, back to the original.
This check is performed at the time of the transaction and in the case of bitcoin, prior to accepting payment (transfer of bitcoin).
Block chain can and is, used for other things than crypto currency. Further, when you are saying bitcoin, you are really saying “A block chain composed of SHA-256 hashes that we agree to represent a value, i.e currency”. Other crypto currencies use other hash algorithms and have other names.