1. In an isothermal process, there is an exchange of heat between the system and the outside environment unlike in adiabatic processes wherein there is none.
2. In an isothermal process, the temperature of the material involved remains the same unlike in adiabatic processes wherein the temperature of the material being compressed may raise.
3. In an isothermal process, heat can be added or released from the system just to keep the same temperature while in an adiabatic process, there’s no heat added or released because maintaining constant temperature will not matter.
4. In an isothermal process, the transformation is slow while in an adiabatic process it is fast
And given below are the thermodynamic relations for isothermal and adiabatic processes.you can go through that also.We know,ΔQ=ΔU+ΔW
and when temperature remains unchanged, there is no change in the internal energy of the system.
So,ΔU=0
So,ΔQ=ΔW
An important characteristics of Isothermal process, the work done is due to the change in the net heat content of the system.
Now, coming to the next part. An Adiabatic Process in a thermodynamic process, where there is no heat transfer. Now, without the heat transfer, ΔQ=0
So, the equation reduces to
ΔW+ΔU=0
ΔW=−ΔU
So, for an Adiabatic Process, the work done is purely due to the change in its internal energy.