Hardware

Frame
Extrusions

Travel [this will talk about v-rollers & linear rails/linear rods/leadscrews/belts]

Wiring

Misc. Hardware [bolts, belts, bearings, ect.]

Electronics
Mainboards

Stepper Drivers

Steppers

Endstops

Heaters

Thermistors

Fans

Power Supply Units

Accessories (Modifications)
Print Surfaces

Probes

Cooling Mounts & Ducts

Lighting