In Pokémon, you have either PP ups or PP Maxes, and they work pretty much the same.
PP Ups:
-Will give a move 1/5 of the max PP
-You will need 5 PP ups to get the max PP of selected move
PP Maxes:
-Will instantly give max PP
-You only need 1 PP max to get the max PP of selected move.
Depending on the base PP, you will get a certain max:
5 PP (Like Explosion) - Max 8 PP
10 PP (Like Earthquake) - Max 16 PP
15 PP (Like Flamethrower) - Max 24 PP
20 PP (Like Swords Dance) - Max 32 PP
25 PP (Like Razor Leaf) - Max 40 PP
30 PP (Like Quick Attack) - Max 48 PP
35 PP (Like Metal Claw) - Max 56 PP
40 PP (Like Growl) - Max 64 PP
Hope this helps!
The Base/Max PP
List of Moves with Base Power