There is a database ("the ledger") composed of blocks of transactions (messages sending bitcoins between addresses). You (a node) can broadcast a transaction you want to make to a network of people with copies of the ledger. (distributed) Miners in the network collect transactions, validate them, and try to solve a hard math problem (Proof of work). When a miner successfully solves the problem they broadcast their solution and the transactions they validated as a block appended to the ledger. Miners are rewarded with bitcoins for their work. People trust the ledger which has valid transactions and the most blocks.