Denotes the following
line is a
comment that is ignored by a
compiler. I know for sure it is a
C++ thing; I'm not too sure of other
programming languages.
Example:
// ATM Program
// This
program simulates an
ATM working environment.
This is a comment that would explain to a person reading the
source code that it was a program that
simulates an ATM. Just an example. Comments can really
say or describe anything.