List of every potion type:

WaterA water bottle.
RegenRestores health over time.
SpeedIncreases player's movement, sprinting speed, jumping length and field of view.
Fire ResistanceGives immunity to damage from fire, lava, and ranged Blaze attacks.
PoisonPoisons an entity, reducing the health to 1 at most.
Instant HealRestores health.
Instant DamageInflicts damage.
WeaknessReduces melee damage.
StrengthIncreases melee damage.
SlownessPlayer's movement is slowed to a crouch.