Items in Jupiter Online generally fall into a few categories:

Equipment — weapons, armor, and accessories, each with a level and mastery requirement before you can wear or wield them, and organized into ascending degrees/grades as you progress.

Consumables — potions, scrolls, and food items that heal you, buff you, or otherwise help you in the field.

Quest items — items tied to a specific quest, usually unable to be sold or traded.

Alchemy materials — elixirs and stones used to add extra options to your equipment (see the Alchemy page for details).

Talismans and dungeon rewards — items like the ones dropped in the Forgotten World, which can be activated in your collection book or sold.

Equipment also has durability, which drops with use and combat; repair it at a blacksmith NPC before it breaks entirely.