What Pascal units meant?

A pascal program consists of the modules which are called as units. The unit is made up of code blocks like functions, subroutines, etc. And these code blocks are made up of data types, variables, statements, procedures, etc. There are two types of units present in Pascal. First one is a built-in unit such as crt. Another one is writing your own units. Pascal allows the programmer to create their own unit that can be used in the program later.