I know that anything with the word "progressive" in it is suspect around here, but they have some advantages over bifocals, along with some disadvantages.
Basically the prescription changes from the bottom of the lens toward the top. The top of the lens is set for long distance vision, and the bottom for close-up. There is always some point along the lens where you can see a specific distance with extreme clarity and focus.
The only downside is that if you are looking at a particular point in space for a long time (ex. a computer screen or TV) then you tend to keep your neck in a very specific spot and it can get stiff and sore.
I have progressives which I use when moving about, driving, etc. I have another prescription which is specifically set for the distance between my eyes and my computer screen. That way I can move my neck around while working or Freeping. My computer glasses are the cheapest I could get with the cheapest frames, and no coatings. I didn't want to spring for two sets of fashionista specs.
Best of luck with your new glasses!