There have been a wide variety of approaches to LTA vehicles over the years. These approaches have been significantly transformed by the availability of new materials for construction, and the choices of lifting gas.
Conventionally, most people will classify LTA vehicles based upon the physical structure. Traditionally there have been three main types of LTA Vehicle; Rigid Airships (including metal-clad) , containing an internal framework, Non-Rigid Airships (often called Blimps) and Semi-Rigid Airships.
More recently, there have been further proposals to construct vehicles which derive most of their lift from Aerostatic principles, but rely very much upon Aerodynamic lift for useful cargo capacity. These more recent concepts have become known generically as Hybrid Airships.
All the vehicles above have been designed as manned vehicles, but there is also a strong push to provide un-manned aerial vehicles (UAVs) using the same principles. These UAVs tend to be marketed as surveillance platforms.