Mining is a key attribute of most cryptocurrencies. To achieve decentralization of a cryptocurrency the responsibility for managing transactions and keeping a so-called ledger is spread to other computers in the network. Participation in keeping particular cryptocurrencies running is realized through so-called mining and all participants are rewarded by digital coins. If you install and set up special software on your computer you will participate in mining. The first minable cryptocurrency was Bitcoin. New Bitcoin transactions are grouped into a block. Each block requires a confirmation. When a block is confirmed then it is appended at the end of a chain of blocks. The chain of blocks is called a blockchain. The blockchain is a ledger where all confirmed transaction can be found. The confirmation of a block requires computer power which is used to resolve a complex cryptography task. Once the task is resolved the block gets confirmed. If you use your computer for block confirmation you will participate in mining. Bitcoin mining is not profitable for individuals nowadays since it requires enormous computer resources. However, you can mine other cryptocurrencies. Mining results in earning digital coins. That is the reward for mining.