Some items are weapons, hats, pants, and accessories, which can be equipped. Other items can be used once or many times for some beneficial or harmful effect. Still others do absolutely nothing, but there aren't very many of that kind.

Some equippable items are enchanted, meaning they convey special benefits to you if you equip them.

Some pairs of items can be combined together with meat paste, and some are used as ingredients in cooking, cocktailcrafting, and meatsmithing.

Enchanted Items
Some items are enchanted, which means that they convey special benefits when they are equipped. These benefits include bonuses to your statistics, maximum HP and MP, permanent effects, and other random things.