A staking pool allows multiple stakeholders to combine their computational resources as a way to increase their chances of being rewarded. In other words, they unite their staking power in the process of verifying and validating new blocks, so they have a higher probability of earning tht block rewards.
Future reading
https://www.publish0x.com/blogx/staking-crypto-part-1-xkmlz
https://topstaking.com/staking-pools/
