trescodanny

Hi, I'm new to this forum so please bear with me on my question? I have played combos for a while now but I bought a Trace Eliot Elf amp, which I love. I'm now looking for advice on the cab to connect it to, now I know TE have a cab specifically for the Elf, but at the moment it's out of my price range. So, my question is, when I look at other cabs, why are there two different outlet holes for the cab? There seems to be a choice on most cabs of a common 1/4 jack connector and then another which looks similar to a DI lead, i.e. female connector? What's the difference in output? Do you connect both, or is this just when using the cab through a PA? Thanks Danny