Mining is the process of validating and recording transactions on the blockchain by utilizing computational power. Validators race to be the first to solve these complex mathematical problems to earn block rewards. Mining uses proof of work that verifies the integrity of the block.
The consensus mechanism allows people to trust each other works on the block. Mining needs a node that is run on a device with extremely high processing power. The downside to mining is the cost of the hardware and overhead as mining uses a lot of electricity.