It gets worse!
In addition to all the different types of discs available, each type is available in different weights, as well!
Discs come in a variety of weights, generally from 150grams all the way up to 180 grams. The heavier the disc, the better it will hold up to strong winds. The lighter the disc, the more apt it will be to glide farther and gain additional distance. There are some disc golfers that carry multiple weights of the same disc in their bag!
FINALLY, discs are also available in different types of plastic. Innova and Discraft have their own varieties, and have their own feeling:
Innova DX Plastic: basically the cheapest plastic. Its not very durable - if you hit a few trees, the plastic will dent and ding, and over time discs fly differently due to being misshapen.
Innova Pro Plastic: This is more durable than DX plastic, and maintains its flight characteristics better over time. In addition, there is a lot of added grip, its much easier to throw than DX plastic
Innova Champion Plastic: This is the ultimate in durability. It lasts forever. It also flies slightly more stable than DX and Pro versions. It isn't particularly grippy, however.
Innova Star Plastic: This is the best of both worlds -- Grippy, Ultra durable discs. Its like the mercedes of the disc golf disc!
Discraft has similar varieties --
Discraft Pro-D (Similar to DX)
Discraft Elite-X (Similar to Pro)
Discraft Elite-Z (Similar to Champion)
Discraft ESP (Similar to Star)
Discraft FLX (a very flexible, durable disc. It flexes easily, hence the name. It does not, however, lose its shape easily.)