A router allows you to share an Internet connection with all the computers on your network. It also allows the sharing of files between said computers. If you have only a single computer at each location, a router would be of little use to you. You might want to read about Remote Desktop. It allows you to access the other (remote) computer over the internet and use it as if you were sitting in front of it.
I need help deciding if I need a network for my computers. Please help me with lay terms on what they do. I have a office away from home with one internet wireless service then my home has a laptop with another wireless internet service. They are 5 mins away from each other. How would it help me to have a router? Tks for your help.