This chapter describes how to compile Pascal programs in separate units. You can also give pc the names of all the units at once, in which case pc compiles all the units, checks for consistency, and links the units in one step.
Separate compilation is different from independent compilation.
In independent compilation, you invoke ld directly, so there is no consistency checking. Independent compilation is not addressed in this guide. The program unit is the source program with the program header. Each program you write can have only one program unit. The program body is the first code that Pascal executes.