A deployable structure is any system that transforms and expands from a volume-efficient stowage state to a fully functional, often significantly larger, operational state. Almost every large structure in space seeks to take advantage of deployment mechanisms to minimize the amount of volume and mass used per launch, but each of these systems have vastly different requirements and thus typically use different methods of deployment. This paper reviews different deployable space structures and systems, as well as some of the specific deployment mechanisms they use. This paper will discuss some of the advantages and disadvantages of those deployment mechanisms and why some deployment mechanism designs might tend to be better for certain systems.