I'm a beginner on Stack Exchange. I have a Stack Overflow account. What is the benefit of reputation count? Do people with more reputation have more knowledge?
The reputation on the SE sites are a rough measurement of how much the community trusts you. As you answer questions or ask them - the community will give you feedback in the form of votes or accepting your answer. The more votes you get the better or more helpful your post was - raising an interesting question is also helpful sometimes as it can make people look again at the way they do things - perhaps your question attracted an excellent answer that helped many many people. For answers I think it is pretty obvious - The better the answer the more votes and reputation you get.
Reputation is sometimes considered a measure of your knowledge (which is not always true). A user with a very high reputation could attempt to answer a question in a field in which he has minimal or no experience - in this case his/her/it's reputation means nothing. However, a high rep user's answer (when they do know what they are talking about) is usually golden as they have worked hard on the site providing great answers and advice for the rest of us. Another use of reputation is to track users progress on the site and award users additional privileges.
Its also FUN! Seeing that you received an upvote or that one of your answers is accepted is a great way to get feedback from the community! If people acknowledge your input it's like a pat on the back and you will be encouraged to continue to contribute good material.
The benefit of reputation is increased privileges. Apart from that it has no concise representable meaning due to the way it is gained, except for maybe high reputation means you spend too much time on this site.
It does not equal knowledge since you usually gain the most reputation by answering simple questions repeatedly. And because of that and the fact that SO still doesn't reward any other community activities (like closevoting) it does not work as the purported rough measure of how much the community trusts you.
A high reputation can get you a t-shirt though.