What is Bitcoin?

Bitcoin is a worldwide cryptocurrency and digital payment system called the first decentralized digital currency, since the system works without a central repository or single administrator.

What is the blockchain?

A blockchain facilitates secure online transactions.  A blockchain is a decentralized and distributed digital ledger that is used to record transactions across many computers so that the record cannot be altered retroactively without the alteration of all subsequent blocks and the collusion of the network.  This allows the participants to verify and audit transactions inexpensively.

What is Bitcoin Mining?

Mining is a record-keeping service. Miners keep the blockchain consistent, complete, and unalterable by repeatedly verifying and collecting newly broadcast transactions into a new group of transactions called a block.  Each block contains a cryptographic hash of the previous block, using the SHA-256 hashing algorithm, which links it to the previous block, thus giving the blockchain its name.

How many bitcoins are in circulation?

Roughly 17 000 000

How many will ever be minted?

21 000 000 bitcoins is the maximum that can be minted and the last will be by 2040.