For example, all I knew about Microsoft Excel before interning was how to make a simple list. Now I know all kinds of more complex things that can be done with this and other programs, along with tons of keyboard shortcuts that save precious time when working on huge projects. However, I am always finding ways to motivate myself and stay focused, and that is an essential skill that can be applied to nearly anything. I also greatly enjoy the work environment of where I intern, and it enlightened me to the fact that an office job can be fun. If you learn absolutely nothing from an internship, and if you do not enjoy it, then the internship is worthless.
Some employers rely on their intern pool for future permanent hires.
If you know which company you want to work for after graduation, then in most cases you would have a better chance of getting hired if you interned there first - as long as you were a good intern who did the job well, of course. Some colleges allow you do an internship in place of taking a class. Usually, you would have to report what you do and hand it to a professor or department supervisor. Colleges that have such a program vary, and so do the employers who participate. Check with your school for more information.