Accessing files from your local hard drive is the easiest thing you can do on a computer, but accessing files on a hard drive on another system is a bit more complicated. Mapping a network drive (Map a Network Drive) is one of the best ways to solve this problem. Forget about sending data via email attachments or sharing USB sticks, network drive mapping lets you set up drives that can be shared and accessed by multiple devices at the same time.
This function is especially useful if you are collaborating with people from remote locations, or for working on group projects with people across time zones. In its current state, it is a very important and useful tool.