A mining pool is a collection of miners working together. Mining Monero is essentially a lottery that someone can win every 2 minutes. Hashrates are the tickets in this metaphor. Much like a real lottery your chances of winning alone are much lower than your chances of winning in a group. Pools provide a more stable return on your mining efforts. Pools have a few different payment methods but they all boil down to rewarding you based on your contribution to the overall hashrate.
We won’t go into the details of what a hash is on this page so just keep thinking of a single hash as a lottery ticket for now. Hashrate is measured in hashes per second. So mining Monero is all about how many hashes (lottery tickets) your computer can generate per second. At the time of this writing the total Monero hashrate is 74,894,000 hashes per second. So thats almost 75 million lottery tickets per every 2 minute lottery. Keep that in mind as you’re evauluating pools. It will give you perspective on how large they are. You’ll see hashrate listed as H/s (hashes per second), KH/s (thousand hashes per second) and MH/s (million hashes per second). There are larger units of measurement but they arn’t applicable to Monero yet.
With that said, choosing a pool is all about hashrate, features, support and uptime. When just starting out, you’ll probably want to pick a pool with a high hashrate to see a faster return. You’ll hear alot of people say that it doesn’t matter what pool you mine at because you’re statistically likely to earn the same amount for your hashrate no matter where you go. This is not quite accurate. Everytime Monero is transferred, a small fee is charged to help incentivize miners to validate transactions. In a larger pool, any reward or winnings needs to be split among more people which means more transfer fees. More transfer fees means less overall reward. Most pools will also charge a fee from 0.5% to 2% of your earnings. This fee goes toward the maintenance and profit of the pool owner, the pool developer, or the core Monero developers.
The following is a very incomplete list of pools. We’re just going to list a few to get your started. Pools are ordered by hashrate from least to greatest at the time of this writing.