Mining
From CoinWiki
Mining is basically transaction verification. When a block of transactions has been validated, the person who successfully solves the problem first receives a reward such as a Bitcoin.
In early days, any computer could be used for mining, but the algorithm is designed to get harder and harder as more people get on the Blockchain so normal computers are now very inefficient at mining. Over time, people found that using computers with mining specific GPUs worked well and now the most efficient miners use Custom Mining Computers, which have a higher hashrate. One can also mine by joining a mining pool.
