what is Box / Suite / Apt #?

Question

for what does it stand Box
Suite
Apt #

Answer 1

All of these are pertaining to a mailing address.
Box is for Post Office Box
Suite & Apt # specify locations at a physical address (ie., 1234 ABC Street, Suite A, OR 1234 ABC Street Apt 567) ...

Answer 2

Post office Box

Answer 3

I think this is what you mean

Box would stand for Post Office Box

Suite is a particular office or store in a shopping center, mall, or office building

Apt# is an apartment number in an apartment building