C: Why do we include header files, which declare but don't define?

Question

At a high level, I understand we use #include statements to make code from other files available to the current file. But I don\'t understand why we include a h

Answer 1

Some people developing libraries do not want to let everyone know full code. They make it a library and then create the headers so everyone could use it. Moreover, @iharob's right, if we include definitions in headers, it's gonna make lots of troubles with code.