Thermodynamics uses the concepts of the isothermal process and adiabatic process to explain the behavior of a thermodynamic system and its relationship to changes in temperature. An isothermal process is a process that occurs at a constant temperature, but other parameters related to the system can be changed accordingly. The adiabatic process describes a process in which no heat transfer occurs between a system and its surroundings. Here, the temperature of the system must be changed to avoid any heat transfer.
This indicates that the main difference between the isothermal and adiabatic processes is that the isothermal process occurs at a constant temperature while the adiabatic process occurs at variable temperatures.