Flat icons are simple PNG images. These cost $.75 each.
Floating Icon
Floating icons have an animated name (or other thing such as a music note or heart). They could also have the entire subject floating with no additional animation. These cost $.80 each.
Simple Animation Icon
Simple animations consist of blinking eyes, a twitching ear, or a moving tail. Most of the subject is static while only one or two parts of it moves. These are $.90 each.
Complex Animation Icon
Complex animations involve all or most of the subject in the icon moving. These can have many more frames than simple animations with each one needing to be drawn from scratch. They are also more difficult to do. These will cost $1.50.