An adiabatic process is a thermodynamic process in which no heat is exchanged between the system and its surroundings. In other words, the system is perfectly insulated so that all changes in the system’s internal energy come from work done on or by the system, not from heat transfer.

Key points:

• No heat transfer: Q=0Q = 0
• Any change in internal energy ΔU\Delta U is due to work WW done on or by the system: ΔU=W\Delta U = W
• Often happens very quickly or in well-insulated systems
• Common in processes like the rapid compression or expansion of gases (e.g., in engines or the atmosphere)

Example:

When you compress a gas quickly inside a cylinder without letting heat in or out, the gas heats up due to the work done on it, but no heat is transferred.