Outside of your regular Weapons, these are the different types of equipment slots to account for.
Repkit Slot
These function as basic healing kits with a cooldown, and can also provide other modifier and/or manufacturer effects.
Ordnance Slot
There's a wide variety of Weapons that fit here, including Grenades, Rocket Launchers, Laser Cannons, Railguns, Chainsaw Launchers, Gatling Guns, Anti-Air Cannons, and more.
Contrary to previous titles, these are tied to a cooldown instead of having a limited amount of ammo.

Class Mod Slot
Class Mods provide additional skill points that are directly applied to your tree, along with stat boosts.
Shield Slot
Damage is eaten by your Shield before its applied directly to you, and there are two kinds of Shields that function a bit differently.
- Energy Shields: These are the default option. Once used up, you must stay safe and avoid damage for a duration before they replenish themselves.
- Armor Shields: Split up into segments which break independently and passively recharge over time, even during combat.
Enhancement Slot
Enhancements grant bonuses to Weapons with the corresponding manufacturer or licensed part, along with universal stat increases that work across the board.
Given that varying part types can be combined together, Enhancements can lead to interesting combos.