Equipment is any piece of item that can be worn to character in the Profile and Costuming tabs of the character menu. TERA uses paper doll inventory where you can drag items from inventory to slots shown on top of character. Alternatively you can right click item in inventory to equip it.
Certain equipment can be equipped by certain classes depending on what the class specializes in. Whether it be the greatest looking bow, a blue robe, or even a laughable sunflower, you will find it all in the category below.
Starter endgame equipment is acquired from a quest when reaching level 65.