OGL Warlock for Starfinder Part 2: Spell Slots

I don't get the spell slot system for D&D 5e's Warlocks warlock spell slot So, what do all those class features mean? And why does the table list is spell slots, rather than spells per day like most spellcasters? Tune warlock best in slot With the help of a Bard, Warlocks can use up to 8 spell slots before a long rest If you have a

warlock spell slot table A simple, customized spell slot tracker for use with druid characters in D&D 5e Customized with class-related images, including the druid class