From Redmoon Advanced Wiki
Normal Items
These are miscellaneous items that are NOT rare, and can usually be purchased at most stores.
Some higher level items can only be found at shops located in more difficult areas.
Weapons
Items held by characters that increases their attacks.
Armor
Items worn by characters that increase their defense.
Accessories
Items worn by characters that boosts certain stats.
Boosters
Items consumed by characters to give a temporary boost of some kind. These cannot be bought from stores, but players often put them in the trader.
These will drop randomly from monsters throughout the game.