ADD or ADHD...what's the difference again?

So I'm having an insanely difficult time concentrating on anything these days. I get to work, and even though I have piles of stuff to do I check my emails (I have 3 email accounts, which, I understand is a bit overkill); check other people's blogs, check my blog, and then go make food. Don't get me wrong, I work too. I actually have a job that makes me more prone to ADD or ADHD or whatever...I seriously get interrupted 900 time a day, at least. I have a lot on my plate, and I guess I just need to learn how to focus. I'm actually going to quit blogging now so I can look up prices to Puerto Rico and buy tickets for a trip I'll be taking in January...then I'm going to work.