I feel stupid having to ask this - but if I don't have it explained I will never learn properly ..so .. Could someone please clarify a few things for me in very (very very) plain english. I know where to put them in the code but don't really understand specifically what they do.

PHP Code:
($row mysql_fetch_array($result) ) 
PHP Code:

also this which I don't really understand at all:
PHP Code: