A Unit Trust essentially is a trust where the Trust Assets are divided into a defined number of units. The income is distributed according to the number of units each individual holds.
A Unit Trust can be the better alternative to a company as it is cheaper to run and start up, plus it has an advantage in terms of Capital Gains Tax. However the Unit Trust does not provide the same level of tax savings as the Family Trust.
The units in a Unit Trust can be freely traded (bought and sold).