M.F.
I used to use both of those in college!
The White-Wash is for ALL WHITE, no printed/screen printed items like socks, sheets, white shirts. It will ruin anything with the slightest bit of color, similar to bleach.
The Whitener & Brightener is for whites that have prints/screen prints/color accents on them. You can also use it on lights, but not on darks.
The White-Wash will remove some stains, but if it's a white item and all cotton, regular bleach works better. The Whitener & Brightener just makes things a little less dingy, not really useful for stain removal.
I hope this helps! Good luck!