there u have the ability to edit each side of a channel (left appart and right appart)
Its a very usefull and powerfull prog as if for instence u have a kick that goes like
DOUB, if u wanna make it fat and heavy u use SOUND FORGE u open the source wave file and work on it to be DDDDOOOOUUUBBBB or how ever u want it to be

ill pass u a toturial that teaches u the basics of how to work on Sound Forge.