Think about bank investment plans for their customers, you deposit an amount of money and it brings back profit into your account. That is how similar staking in cryptocurrencies are. In cryptos, from a non-technical point of view staking is being paid for holding a specific kind of coin.
From a technical view, Staking is the act of holding coins in a cryptocurrency wallet, to help the functioning of a blockchain network. Users who lock in their funds with a specific coin or project, do this with the intention of receiving rewards in return whereas helping support a blockchain network.
Minning is stressful, uneasy and expensive. Miners have to buy expensive software and hardware, staying online 24/7 and consuming a lot of power. Instead of miners decrypting cryptographic puzzles using too much computing power to authenticate transactions as they do with PoW, with PoS subscribers with existing coins verify transactions in proportion to the number of coins they have locked in a staking wallet.
When staking a coin, what you need to do is to keep a specified amount of coins locked up for a certain period of time. As long as a user does not quite form this, they will keep earning newly minted coins. The amount to keep is not exact for all crypto projects, they vary from crypto project to crypto project.