HDM what?

So my husband is an electronics geek as you already know. I have to be honest, I don't see much difference from one gadget to the next. I'm sure it shames him to hear me say "hun, I just don't care how many watts the sub woofer puts out" i don't even know if sub woofers put out watts, so yah... 

I am also not a gamer, We had an xbox way back before the Wii came out and i was upset with the games, they were all either war games, driving games, sports games or music games. So when Nintendo came out with the Wii i got excited because I enjoy Mario, I also enjoy family games. The Xbox had no family appropriate games at the time. Fast forward 4ish years and The xbox comes out with Kinect and suddenly has family games. Which just made my husband beg even more for an xbox.  He somehow ended up with one with this tax return, i'm not sure how, he brought it home one day and that was it. I really don't see the point, but that's me. One thing he just keeps talking about, and has been since we got our tv 4 years ago was HDMI. I really don't know what it means or what it does other than he keeps saying you can put an HDMI in here or connect it via HDMI.  honestly... I don't get it, but I'm sure he says the same thing about me and all my rants about running and running shoes...