The parts of the trike conversion called "suspension" suspend the driver and passenger from the ground. This keeps your body and spine from feeling every single bump and hole in the road. There are two primary types of suspension in practice on trike conversions: independent suspension and fixed axle suspension.
A fixed axle suspension converts most belt or chain driven motorcycles into a trike. With a fixed axle the left and right side are tied together. The conversion takes only a few hours by a competent mechanic. Many of these also have a limited-slip differential (LSD). LSD is a type of differential gear arrangement that allows for some difference in angular velocity of the output shafts. This means that the wheels both stay powered when you need them to.
In an automobile, such limited-slip differentials are sometimes used in place of a standard differential, where they convey certain dynamic advantages, at the expense of greater complexity