Voting is how Steemit learns what is good and what is not good content, things up voted a lot will get sent to the Hot tab making Steemit's content better than other blogs. Up voting also tells Steemit how good individuals are at finding good content and awards them reputation and steem power for doing so. However when you vote your steem power is depleted slightly so use your up votes wisely. Another thing is if you have more than 500 steem power you can choose what percentage of up vote you give out so you don't spend 100% up vote on every click. I hope this answers your questions. I have one more trick up my sleeve for you. this link will tell you how much steem power you have and what percent vote you have left. https://steemd.com/@jayasstarbazaar. I have put a good effort into answering your question so I would very much appreciate an up vote, follow and resteem friend.