What is the difference in Charcoal and "Ativated Charcoal"?

Question

Also, do they both absorb odor?

Answer 1

Charcoal is the blackish residue consisting of impure carbon obtained by removing water and other volatile constituents from animal and vegetation substances.

Activated charcoal is processed carbon that makes it extremely porous (full of holes) and thus giving it a large surface area available for adsorption or chemical reactions.

Absorb odor? I'm not sure what you mean here...  

Answer 2

Big difference.  If you're looking for a product to eliminate cat odor from litter box, go with activated carbon filters available with Innofresh PET odor absorbers.   Completely fragrance free and they really work.  I've got cats and wouldn't be without these.  Made by Innofresh and you can get on line and I think some pet stores.   For litter box, nothing better and without those citrus gels that stink!