Plastic Is Different
Plastic refers to the type of plastic, like PLA or ASA.
The guys who make filament probably do not make the plastic. They get a huge bunch of pellets of the plastic from some other manufacturer. It’s probably just the plastic. The filament maker adds stoff. Color and other things. The color may be different. Blue PLA from eSun may be different from blue PLA fron Sunlu. Both of them may get the PLA pellets from BASF, but they could use a different thing to make it blue. Along with the color almost all filament has other stuff in it. This other stuff is particular to a filament maker, may change, and hopefully makes their plastic better.
PLA+ means nothing. It is PLA with stuff. No industry meaning to +. Each manufacturer adds their own stuff to make it +.
There is no best. There are only a few companies that make the pellets and there are probably many filament makers that use the same pellets. The stuff they add is different, but it can change, or it could be the same as some other filament maker. The major difference is the care taken when turning the pellets, color, and stuff into filament. Is the machinery the maker is using well maintained? Is the guy running the machine paying attention? Did the guy making the filament you like have a tough night out with the boys and come to work hungover?
White filament normally uses titanium dioxide to color it. Titanium dioxide is more abrasive that most other colors.
Glow in the dark has little particles of glow in the dark. It is extremely abrasive. A single print can ruin a brass nozzle.
Now we come to the main plastic. There are a bunch that are commonly used by hobbyists. Each of then has different properties. Some of the properties affect how they print. Some properties affect how the thing behaves when you use it.
This gives you an idea of some basics.
Quite often it is helpful to know what plastic it is. Some tend to come off the plate and curl, some like an enclosure.
Most early makers use PLA, it’s the easiest. Some do not. I have been wrong guessing a new maker is referring to PLA. Don’t make me guess.