Hi ancath!
This is a very good question! Before I talk about the differences between the resorts, I would like to say that all guests staying at any Walt Disney World Resort (in Value, Moderate or Deluxe hotels) receive resort benefits such as complimentary use of the Disney Transportation System around the resort, and to/from the airport, use of the Extra Magic Hours at the theme parks and free package delivery from the theme parks and Downtown Disney to your resort. Every Disney Resort has unique and special theming, and staying at a Disney Resort keeps you immersed in the magic for the length of your stay.
Value Resorts are very family-friendly with bright, colourful, larger-than-life theming. Large themed pools, food courts, and bus transportation around the resort.
Moderate Resorts have lovely theming, pools with slides, other pools and numerous recreational facilities, full-service restaurants and food courts, bus transportation (and boat transportation from some resorts), larger guest rooms.
You may wish to look at the full details for all
Disney Resorts to see which ones visually appeal to you. If you would like me to answer more fully about any specific resorts please come back and ask me!