A process is the act of running a computer program. If you are using Notepad to edit two separate documents and both windows are open, these are two separate processes. If you also have Internet Explorer running, that's a third process.
Some applications (such as Microsoft Office) may be composed of several processes. Also, the operating system has many processes that help it keep track of everything going on in the background, where you really don't see what the computer is doing.
Hold down the Alt, Control and Delete key simultaneously. When the Window
on the screen gives us several choice, pick Task List. Click on the tab that
says Processes. Find the listings for the following three entries:
Copy the UserName, and Memory usage for each of these three processes. Also go online and find out what these three processes do. A basic search on Google will be sufficient.