Mobile cranes have been around since the early 1900s and helped countless constructions around the world. It all started with an idea of making a fixed crane easily transportable. The drawback is that the cranes have less load capacity, but its versatility makes mobile cranes still as useful. 

On top of that, another advantage of mobile cranes is that they do not require any special foundations or footings. There is no need to 'erect' a mobile crane. 

A typical mobile crane can be divided into two sections, carrier and boom. Carrier is the lower section of a mobile crane that allows the crane to be transportable. Boom is the upper section where it is responsible to carry and trasnport loads. Nowadays, mobile cranes are available in various carriers and booms, depending on the usages. Carriers are available for different type of terrains, while booms are available for different load capacity or height requirements. For more information on what are the various types of carriers and booms, check Know-your-Cranes discussions here