The #define preprocessor directive has the form:
#define identifier token-string
The preprocessor substitutes the token string everywhere in the
program that it finds the identifier except within comments,
character constants, or string constants.
Macro replacements are defined in a #define directive of the
following form:
#define name([parm1[,parm2,...]]) token-string
Within the program, all macro references that have the following
form are replaced by the token string. The arguments in the macro
reference replace the corresponding parameters in the token string.
name([arg1[,arg2,...]])