Stranded
Stranded is primarily used for building patch cables. The core of the conductors is comprised of many strands of copper enabling greater flexibility without damaging the copper conductor cores.

Solid
Solid cable is primarily used for in-wall or permanent applications. The copper conductor cores are comprised of a single solid strand of copper. This allows for greater transmission distances, however, it can not be flexed repeatedly without causing damage.

Plenum
Plenum is primarily used for in-wall or permanent applications where the local building codes require that plenum be used. Plenum is essentially the same as solid except the jacketing is comprised of a PVC Teflon mix. This plenum jacket is a low smoke/flame retardant jacket that reduces the amount of toxic fumes that are released into air in the case of a fire.