C++ programs are usually a collection of some C++ code spread across one or multiple source and header files. Source files, by convention, have the .cpp extension, and header files, by convention, have the .h extension. Other extensions are also possible. Both header and source files are regular text files containing some C++ source code. The C++ compiler is a program that compiles these files and turns them into object files. A linker then links object files together to create an executable file or a library. ...