When a wheel alignment is performed what componets on the truck do they make adjustments to?

 

Have a look at this article it might fill you in a little:
http://www.familycar.com/alignment.htm

A couple of other notes:
Adjusting camber can be achived by adjusting the bushing that the bolt connecting the lower support arm to the frame passes through ....... " a lower support arm and a pivot bolt extending from the cross-frame, the pivot bolt extending perpendicular to the longitudinal length of the cross-frame, improved means of adjustably supporting the lower support arm to the pivot bolt as a means of adjusting the front wheel camber including a bushing having a cylindrical external surface rotatably received in the opening of the lower support arm and having an opening therethrough eccentric to the cylindrical surface, the bushing receiving the pivot bolt in the longitudinal opening and means of rotatably positioning the bushing on the pivot bolt to longitudinally position the lower support arm. "
Adjusting Toe in this is achieved by adjusting you tie rods on either side in or out.