Some of the essential elements are:
Launch track: It is the section where the train is accelerated to its full speed in a matter of seconds.
Lift hill: It transports the roller coaster train to an elevated point.
Train: It is the vehicle which transports passengers around a roller coaster's circuit.
In roller coasters, the two forms of energy that are most important are gravitational potential energy and kinetic energy.
The gravitational potential energy is given by:

And the kinetic energy is given by:

From these equations we can conclude that they are important since they influence on the mass, the speed and the height. Which are part of the two forms of energy.