The Compile menu

The ”Compile” menu contains all entries related to compiling a program or unit.

Compile: (Alt-F9) Compiles the contents of the active window, irrespective of the primary file setting.
Make: (F9) Compiles the contents of the active window, and any files that the unit or program depends on and that were modified since the last compile. If the primary file was set, the primary file is compiled instead.
Build: Compiles the contents of the active window, and any files that the unit or program depends on, whether they were modified or not. If the primary file was set, the primary file is compiled instead.
Target: Sets the target operating system for which the program should be compiled.
Primary file: Sets the primary file. If set, any run or compile command will act on the primary file instead of on the active window. The primary file need not be loaded in the IDE for this to have effect.
Clear primary file: Clears the primary file. After this command, any run or compile action will act on the active window.
Compiler messages: (F12) Displays the compiler messages window. This window will display the messages generated by the compiler during the most recent compile.