// comment text

/* multiple line comment text */

Comments are notes by the author explaining what the script does, and are ignored by the interpreter. A comment consisting of a single line is preceded by a double slash (//):

Code:
// This is a single-line comment.

...and a multiple line comment is preceded by a /* and followed by a */:

Code:
/* This is a multiple line comment. It can contain whatever letters and characters you like and span as many lines as you like. */