There are times when I will right click on the taskbar down bottom and launch the task manager (or use the hotkey). This will bring up a list of "processes" that are running. For example, at the moment, my home machine has 51 processes running. I can look at the list and recognize some of them - a skill that comes with time - but there are certainly others that are foreign to me.
There are plenty of resources for for this, including just Googling the name of the process...but I have found that the site below provides some great information on tasks, and usually just go directly there.