The #define directive uses macros for defining constant values. What does this mean...?

Answer 1

hi

Answer 2

It pretty much means your compiler will go through your code when compiling and replace every instance of that word with what you define it as before interpreting your code.

For example:

#define TEN 10

cout << TEN;

Will cause the system to replace TEN with the number 10 before the code is processed.

Here is a more in depth explaination: http://www.cplusplus.com/doc/tutorial/preprocessor/