Comments are usually non executable statements which are meant for the programmers own convenience.
A comment is usually explanation regrading the statement. The compiler ignores these comments when it translates the program into executable code.
Basically there are two types of comments in C Language.
Single line comment allows only one line. these comments must begin with //(double slash).
If the comment exceeds more than one line, multi line comment is used. Multi line comment begin with /* and end with */