too simplify cause i know your new...not cause i think your stupid:
there are basically 2 types of suspensions
Leaf spring: pretty self explanatory, just look at the rear suspension of almost every truck. the leaf spring connects to the frame in two places and the axle is centered between those two places. can be either on top of (SUA, Spring Under Axle) or below (SOA, Spring Over Axle). This is the type of suspension you will see on on your F250, used in both front and rear applications.
Linked suspension: could be 4 link or 3 link. 4 is most popular. Kinda like the front suspension on a jeep cherokee sport. rather than using leafs, it uses coils or airshocks or coilovers ( a combination of the two). the links serve to hold the axle in place and transfer the motion from the axle too the frame. Triangulation means that the upper two links form a \/ shape and the lowers form a /\ shape. these triangles help keep the axle from moving side to side. a non triangulated link set up has upper and lower links set up like this ll ll and the axle will slide side to side. to stop that people add a track bar (also called panhard) it simply connects the left side of the axle to the right side (or vice versa) of the fram and keeps the axle in place.
your F150 is kind of....gets comlicated....a 3 link set up. the two radius arms being 2 links and the hinge in the middle being the 3rd link. lol...sorrry....i hope that didnt confuse you, fords not exactly a good example but i know your familiar with it.