A generic term about a travel trailer that is more about staying at one location for a longer time than traveling around. Kind of like a temporary home. I have no idea what the actual difference is.
A park model is not "self-contained" and will not have all the travel-related systems like holding tanks,since they are designed for use only at a modular home park. They often have lofts like the so-called "tiny homes" as well. Here is a good summary of trailer types: