Emulator Overview
An emulator is a virtual system. In the case of gaming emulators, they are virtual gaming systems like having a Nintendo 64 console or a Wii or a GameCube on your computer. These virtual systems (emulators) are used to play roms (backups) of your games for those systems.
In the following videos, I will go over how to use them and incorporate them into a frontend called LaunchBox.