The job of a vehicle's suspension is to maximize the friction between the tires and the road surface, to provide steering stability with good handling, and to ensure the comfort of the passengers. These parts include ball joints, control arms and bushings, shocks and struts, springs, sway bars and links.
The steering system is comprised of components, linkages, etc. which will allow a vehicle to follow the desired course. Steering parts include tie rods, steering gears, center links, idler arms, and steering stabilizers. Power steering includes pumps, hoses, and belts in addition.
Worn parts in these systems frequently have no obvious symptoms so even without problems they should be inspected annually. Symptoms, when they do occur, would include clunks, rattles, squeaks, soft or mushy ride, sloppy steering, and uneven tire wear.
Improper wheel alignment can cause poor handling or uneven tire wear. Alignments will not be effective without first addressing any worn parts.