Suspension

Can anyone explain to me the difference in suspension setups 4 link, coil over etc?

A four link, unlike a leaf spring pack, is made up of bars. The usual arrangement is one forward facing bar on each side of the axle to keep your axle from moving forward or backward. These bars will be the two most outward mounted bars. Then there are two more bars on each side of the axle that both bolt together at one point in front of the axle on a crossmember. These bars keep the axle from moving left or right. This type of suspension will not hold up by itself and is used with some other type of suspension such as airbags, hydraulics, or a coilover.

A coilover is almost the same as a spring and shock setup, only the spring is mounted to the shock itself.