From the introduction:
The Ranger Spell Deck I contains all the Pathfinder RPG core ranger class spells from first level through fourth level in a thick poker card deck format.
This spell deck allows players to easily reference their class spells and even manage their spell slots with visual representation. These spell cards have the full spell text and mechanics within, so no need to hunt down the rules, you have them at your fingertips!
You can even use multiple decks to represent your entire number of slots and memorized spells!