Car Camping - Easiest - You literally camp next to your car. You don't have to carry anything. This allows you to bring just about anything. So go ahead and bring your pillow, books, and other items to make your trip more enjoyable. Normally you are camping at official campgrounds.
Example: Watchman campground at Zion.
Official Campgrounds - moderate - I am writing about campgrounds you have to backpack to get to. You need to carry anything the campground does not provide. Many campgrounds have some amenities. Leave the books, pillows, etc. at home.
Example: Campground at Havasupai.
Unofficial Campgrounds - toughest - Generally these are backpacks into an area of interest. You make your own campsite. There is nothing but you and the mountains. You have to be self sufficient. Don't take anything that is not essential. Many times mountain climbers backpack into a base camp and from there bag nearby peaks.
Example: Dusy Basin in the Sierra