Mining
Mining is the job a Proof of Work network uses to check transactions and pack them into blocks. Miners run powerful hardware and race to solve a cryptographic puzzle. The winner adds the block and collects the reward.
In Bitcoin, mining is still the only way new coins enter circulation. The block reward is cut in half every 210,000 blocks, and that cut is the halving.
Example
Someone offers you "cloud mining" with a guaranteed monthly income. That is a red flag. A miner earns based on the block reward, the coin price and the cost of hardware and power, so nobody can guarantee a result.
What not to do
Do not buy contracts or "farms" that promise fixed profit. Count the costs first, then look at the income.