TL;DR: You use the computing power of a computer to help secure transactions on a blockchain. You are remunerated only if you win the validation of a block, and this remuneration remains uncertain.
The principle of mining
Mining consists of using the computing power of a computer to help secure transactions within the framework of a blockchain. You can participate by investing in computer hardware offering computing power and by downloading open-source software.
Block validation
Remuneration occurs when you win the validation of a block. The available information does not describe the technical steps involved in this validation or the algorithms used.
Uncertain remuneration
You are not automatically remunerated because your computer is using its computing power. The system remunerates you when you win the validation of a block. This remuneration may take the form of an allocation of cryptocurrencies and is uncertain in nature.
Fees related to transactions
The remuneration allocated by the system is distinct from the fees that may be freely granted by the beneficiaries of a transaction. These fees constitute a separate mechanism from the reward linked to the validation of a block.