amps cabs and heads

can someone explain to me the difference between amps cabs and heads? i am fairly certain i know the difference, but i figured if someone can offer a detailed explanation i will take the free advice.

i'm assuming that an "amp" is an amplifier and speaker wrapped into one box, and that a head unit / cabinet is a separate amplifier (head unit) and speaker (in cabinet).

one question i have: how are a head and cab connected together?

The Amp head is the amplifier and circuitry in one box. The cab is the speakers.

Oh yeah. They are connected with a speaker cable from the head to the cab.

An amp and speakers in one box is called a combo amp.

I should have answered these in one post, I'm not sure why I did it this way...I'm just silly I guess.

what kind of speaker cable? so basically the output from the amp head is an audio signal that could be played on any speaker, not just a "guitar amp" specified speaker cabinet?

as opposed to the output from the guitar which is an electrical signal?

In theory you could use any speaker cabinet, but you run the risk of blowing the speakers if they can't handle the power of the amp. I just use a regular 1/4 inch to 1/4 inch speaker cable for my half stack. It was thrown in when I purchased the half stack at the local music store. I have an 8 ohm cab so I set my head to 8 ohms (mine is switchable) and I go from the mono out of the head to the input on the cab. I think my amp (line 6 HD 147) can run 8 cabs or something ridiculous like that.

EDIT: Make that 4 cabs. Not so impressive now.