You need a file called a makefile to tell make what to do. Most often, the makefile tells make how to compile and link a program. ... If a header file has changed, each C source file that includes the header file must be recompiled to be safe. Each compilation produces an object file corresponding to the source file.

Is a makefile necessary?

A makefile is useful because (if properly defined) allows recompiling only what is needed when you make a change. In a large project rebuilding the program can take some serious time because there will be many files to be compiled and linked and there will be documentation, tests, examples etc.

What is the point of a makefile?

The purpose of a makefile is to be easily build an executable that might take many commands to create (which would be a pain to compile over and over again manually).