The compressor on the left forces air (through the blue lined tubes in the foreground) to the yellow combustion section on the right (where the air and fuel mixture ignite). Expanding hot gasses (shown in orange) are forced toward the left through two sets of turbine wheels. (Small blades in the wheels forces them to spin as the gasses race toward the white exhaust). One set of turbine wheels turns the (Green) gearbox which powers the helicopter rotors. (The other set turns the compressor).