Bitcoin miners use special software and hardware to do computations to solve math problems and earn Bitcoins or other cybercurrencies in exchange. This gives incentives for people to mine.
Bitcoin miners approve transactions during bitcoin exchanges. This helps keep the Bitcoin exchange network secure and stable.
Blockchain is the process of Bitcoin mining. It’s adding transaction records of past transactions to Bitcoin’s public ledger. This ledger of past transactions is as it is a chain of blocks therefore called block chain. The block chain confirms transactions to the the network as done.
Bitcoin mining nodes use the block chain to differentiate legitimate Bitcoin transactions from attempts to re-spend coins that have already been spent.