Blockchain is a critical part of the bitcoin peer-to-peer payment system. The bitcoin system works using a blockchain ledger to record transactions. The blockchain ledger helps to provide transparency for transactions.
Although many bitcoin transactions are in some ways anonymous, the blockchain ledger can link individuals and companies to bitcoin purchases and ownership by allowing individual parties, called miners, to process payments and verify transactions. Rather than a central company presiding over the use of bitcoin, these blockchain originators serve central roles in the management and administration of this alternative currency system.
The system can also be used to verify transparancy in other transactions.