The Carnot cycle represents an idealized, reversible thermodynamic power cycle operating between two constant-temperature thermal reservoirs (T_H and T_C). Plotted on pressure-volume (P-V) coordinates, the cycle consists of four distinct state transitions: isothermal expansion (1→2), isentropic expansion (2→3), isothermal compression (3→4), and isentropic compression (4→1). The enclosed area represents the net mechanical work output per cycle.