ASCII CODE
American Standard Code for Information Interchange (ASCII). Computers only understand two things, zero 0 and one 1. Therefore it was necessary for humans to develop an interface so computers can understand what humans do. What resulted is the ASCII code.
A SYSTEM UNIT WITH IT'S COVER REMOVED
This is a system unit (computer) with the cover removed. This diagram is useful in understanding how the hardware inside a computer works.
FILES AND FOLDERS DIAGRAM
This is a diagram of the Hierarchical relationship between files and folders