The punctuation and special characters in the C character set have various uses, from organizing program text to defining the tasks that the compiler or the compiled program carries out. They do not specify an operation to be performed. Some punctuation symbols are also operators (see Operators in Chapter 4). The compiler determines their use from context.
Syntax
punctuator : one of
[ ] ( ) { } * , : = ; ... #
These characters have special meanings in C. Their uses are described throughout this book. The pound sign (#) can occur only in preprocessing directives.