Baking soda vs. baking powder

Baking soda vs. baking powder

I've heard of several different 'solutions' for some unrelated problems, was wondering if you all could clarify for me. Baking soda/powder to absorb odors. (Which one, and is there a difference between the two?) Putting baby/talc powder on shirt collars to prevent collar stains. (I just started a serving job, but I only have one shirt, so I'd like to keep it as nice looking as possible. Would applying baking powder do the same thing?) I've also heard of people using baking soda to wash hair. Along that line, i've also heard of people putting baby powder on hair to absorb grease as a quick fix if you don't have time to shampoo. Anything you know to be true/not? This is such an informative community, i've learned so much. Thanks!
Pictures of my garden

Pictures of my garden

‘Ello

‘Ello

upholstery cleaner RAVE!

upholstery cleaner RAVE!

Succulent ID

Succulent ID

hehe.. another name search please..

hehe.. another name search please..

my rooooom.

my rooooom.