Hi, witnesses basically verify blocks on the Hive blockchain, so they make sure that everything runs in order and works out smoothly. The following post is really good and pretty much sumarizes what witnesses do https://hive.blog/hive-102930/@quochuy/witness-earnings-monthly-report-september-2023
BUT you don't get any rewards for voting witnesses. Nevertheless you should vote for them, as it basically says that you are trusting this person to keep the Hive blockchain running and make good decisions about the future of the chain .
You can vote for witnesses on peakd, ecency, hive.blog, inside keychain or even on the page i provide primersion.com. There are plenty of such sites you can check your votes and vote for witnesses - but make sure to always use a site which provides keychain or hiveauth support and don't enter your keys directly.
Have a nice weekend and if you got more questions, feel free to ask at any time🙂
Is there a limit as to how many witnesses I can vote for?
Is there a consensus about how many witnesses someone should vote for?
So far, I have only voted for witnesses I recognize within the top 100 or so profiles listed.
You can vote for up to 30 witnesses. How many you actually vote is up to you, but only the top 20 witnesses with the most votes are verifying blocks (plus one backup witness chosen randomly among all others).