What is adiabatic process?

If a thermodynamic system is perfectly insulated from the surroundings and undergoes a process in such a way that no exchange of heat takes place between it and the surroundings, the process is said to be adiabatic process. In such process no heat is allowed either to enter the system or to leave it, but all along the process, there is a change in temperature. If a gad is suddenly compressed , the external work done upon it, increases it's internal energy and consequently it's temperature falls. Thus there is no exchange of heat between the gas and surroundings, being perfectly insulated from each other, and hence the processes are adiabatic. The compressions and rarefactions produced in air during the propagation of sound waves is also an example of adiabatic process. The sudden expansion of the enclosed air into the atmosphere when a motor tyre bursts, is approximately adiabatic and hence the tyre is cooled. Thus all processes that take place quickly or suddenly are adiabatic process. During adiabatic process , no heat enters or leave the system , but temperature changes, because work is done at the cost of internal energy.