This might be a stupid question but I'm not an expert with amps. Suppose I got an Orange Tiny Terror could I play with just the head or do I need a cab. My feeling is that I would be able to play with just the head, but I'm not completely sure.
you'll need a cab. there's no speakers in a head.

edit: ^holy similar
i used to be a mod, then i took an arrow in the knee.
The head of any amp is just the amplifier. You will need a speaker cab to go with it.