Mining is an algorithmic computing process in which so-called miners generate blocks and attach them to a generally applicable blockchain protocol. This process is called mining, analogous to gold digging.
The miners and nodes control the network and verify transactions. This makes it almost impossible for the network to be controlled by a central location, since the miners keep the network running independently of one another. As compensation for the computing power and the electricity costs that the miners use for this, they receive a proportionate reward in the form of a coin (e.g. Bitcoin -> Bitcoin mining) in a wallet.