What is cryptocurrency mining?
"Mining" is the method by which a new unit of cryptocurrency enters circulation; you can think of it as being similar to the way a central bank issues traditional currency. However, the way this happens is not through a printing press; it is done through a technically complex process where large computational resources are applied to solve complex mathematical equations.
While operating, miners act as actual validators, as they examine blocks of cryptocurrency transactions to ensure that no one is trying to spend the same currency twice. The miner is compensated with a unit (or subunit) of the newly produced cryptocurrency as a reward for helping to ensure the overall validity of the currency.