Etymology

Punctuation

Punctuation is used in programming languages, as it is in natural languages.  The punctuation marks listed here have syntactic meaning to the compiler.  Operators are listed separately. 

;
The semicolon is used in C to terminate an expression statement.
{ }
Braces are used in C to group a sequence of statements.  Braces should always be used in matched pairs.
( )
Parentheses are used in C to group parts of an expression, and as syntactic elements in if and while statements.  Parentheses should always be used in matched pairs.  Parentheses are also used as operators for type casting.
:
The colon is used in C to terminate a statement label.  The color is also used in the conditional (? :) operator.
,
The comma is used in C to separate elements of an argument list.  The comma is also used as the sequence operator.