Most full sus. kits have springs, struts, shocks, and some come with sway bars.:
Coilovers are usually spring-over-strut design that are adjustable that take the place of your stock struts.
Sway bars are the bars under your car that attach usually to each control arm and mount to the frame to limit the body roll.
Stress bars are the bars that you can add to like the upper sturt mounting point to stiffin the chassis.
Camber adjustment kits allow the adjustment of camber usually needed when you lower your car
All of which are for making your car look better and most importantly, handle better.