Welcome, cladding is the plastic stuff you have around the bottom 1/3 of your truck, the bed covers, sail panels and cargo boxes are made of the same material.
the plastic is defective and very prone to fading and generally looking awful.
Gatorback is a paint-like coating that makes it look much better. If your truck is still under warranty or sometimes not, you can get it coated free.
check around the forums, there is a lot of information of the subject.
Thanxs for the info DaytonaZ71.. The rear top i guess you guys call them sail panels cargo box top look different from the bottom, kinda like dried up salt water on the road during the winter..