This animation illustrates the volume of one "working chamber" during a full operating cycle. The chamber first passes over the intake ports, then compresses the air/fuel mixture, the ignition fires the sparkplugs near top dead center, the combustion event pushes the rotor and eccentric shaft through the power stroke, and then the combustion gasses are released as the chamber passes over the exhaust port. Notice the sequence of ignition events, which involves three different sparks. You can learn more about this in Rotary Engine 101.