It may be that bed liner spray is the most popular way to line truck beds. A spray on pickup bed liner is sprayed on the bed and becomes a permanent coating for the truck bed. Most often the bed liner paint is applied professionally, but material is out there for a do it yourself bed liner .
Two big names in spray on bed liners are Line-X and Rhino Coatings. There is probably a franchisee close to where you live. Both make durable attractive finishes. Line-X finishes are smoother in texture. Rhino offers several different finish options.
A spray on bed liner can usually be finished in two or three hours.(That's at a pro shop of course. It would take me a whole lot longer than that....) So it's usually a one day turn-around time. Rhino Coatings and Line-X both advertise their finishes as environmentally friendly, since the materials are high percentage solids.
Whether you hire someone to apply your bed liner spray, or do it yourself, masking of the bed is very important. The spray bed liner material is meant to really stick and be hard to remove. So you don't want over-spray and spray drift ending up all over your truck. Over-spray can be removed, but it's better not to get it there in the first place.
The bed liner paint material available to us to apply ourselves is usually described as polyurethane.
So bed liner coating is a tough paint material with some kind of texture in it.
Different manufacturers recommend different spray equipment. Some recommend an undercoating gun. Others suggest a particular nozzle. Whatever product you choose, check the recommendations.
Another option is a roll on bed liner kit. Coatings designed for roll on are available. My sons just installed a roll on bed liner in our old family truck. The bed liner looks almost as good as my neighbor's Line-x bed liner. The only problem is it makes the rest of my truck look bad!
Be warned. An inexpensive roll on bed liner might cost you a new paint job. You'll want to make the rest of your truck look as good as the new bed!