The #include directive, as you might recall, indicates to the compiler that you want it to treat an external file as part of the file being compiled. The basic syntax for this directive is as follows:
Note that there is no semicolon at the end of the line, although you can make a comment after it using the // or /* comment */ markers for C commenting. The types of characters delimiting the filename are significant.
The first use indicates that you want to look for <filename.h> in the standard include directories. These are usually added in the environment of the compiler during installation and may be found in a folder on the path of the compiler set called include.
For example, ...