Question : Oracle SQL -- NULL VS COALESCE

Can somebody explain me the diff between, NULL AND COALESCE statements. When to use NULL or COALESCE, and their performance effects.. maybe with an example...
Thanks@

Answer : Oracle SQL -- NULL VS COALESCE

Just did a double check and there is indeed a difference.

http://stackoverflow.com/questions/950084/oracle-differences-between-nvl-and-coalesce

In short, COALESCE is an ANSI standard supported by all major DBMS, and is faster because it stops evaluation as soon as a non-null value is found.  Always use COALESCE.