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.