I think this is like asking what money is for? Saving or spending.
And then not including, investing, borrowing, lending, bribing, leverage, security, earning, sharing, stealing, winning, loosing etc etc etc. It's so diverse. The more you know about it, the more you can use it for. The more you study, the better you become at using it. Like lots of things in life, if you choose to remain ignorant of it, you will loose out.
Speaking is another thing that has such a huge diversity of uses...