In order to represent the real world inside a computer, programming languages use numbers, both integer and real, letters and words and logical expressions. All these data must be stored somewhere where they cannot be confused. Variable type helps a user avoid writing statements that are logically nonsensical, saving effort, and simultaneously helping the computer to understand what the programmer seeks to do.
Lectures developed for [CSE2] were developed by Brian Chen, Brian Davison, and Edwin Kay. Lectures may be used for other courses by permission only (Contact Brian Chen).