What It Takes To Reboot a Computer

Sometimes I have several projects going at once on my computer, and it will sometimes freeze up. Of course, this is very annoying, and I try to solve the problem as quickly as possible. When my computer started acting strangely, I had a friend come over to take a look at it. He said that what I needed to do was to reboot computer, and he had me take a few precautionary measures to protect my data. Once he was finished, we reinstalled the programs, and it started working just fine. I was very grateful for his help, and I know how to do it myself if I need to.