it's for everything. just a different system from the VAT system europe uses. everything is taxed at purchase. fun part is not all things are taxed at the same rate,.. beer is taxed higher than fruit for instance. it's always a bit of a mystery what you're going to actually pay when you buy something which is what i like about the VAT system.
Very much depends.
Most food is not taxed in my state.
This is also true here in Texas the only food that is taxes besides alcohol is soda all prerared food bought in restaurants is taxed. Personal items (shampoo, deodarant, tootpaste) are tax free in Texas also.