These days, most consoles share the same games with only a few exceptions. Developers have no qualms about making their titles available on anything and everything, seeing as that generates the most in sales, but some are limited to specific systems.
These are the games that draw a player to one console or another. If someone is on the fence as to which one to buy, playing the latest and greatest in a particular series might be the icing on the cake that pushes them to choose a PS4 over an Xbox One or Nintendo Switch.
When it comes to exclusive on the PS4, the industry was gifted with some of the best of the bunch in 2018. These are the games people bought the system to play, which is saying something considering the cost of a new console. If someone goes out and spends $300+ just to play a specific title, there's got to be a reason for it.
Exclusive titles are nothing new, but the ones dropped for the PS4 in 2018 were pretty amazing. They're damn near all recommendable, but only one can be called the all-out best.