What is on the inside of rocket engines?

The inside of rocket engines contains several key components, including combustion chambers, nozzles, and fuel injectors. In the combustion chamber, propellant (fuel and oxidizer) is ignited, producing high-pressure gases that expand and are expelled through the nozzle to generate thrust. Additionally, cooling channels may be integrated to manage the extreme temperatures generated during combustion. Various sensors and valves are also present to control the flow of propellants and monitor engine performance.