Why do rockets need ignited?

Rockets need to be ignited to initiate the combustion of propellant, which produces the high-pressure and high-temperature gases necessary for thrust. This combustion process generates the force that propels the rocket upward by expelling gases at high speed in the opposite direction, according to Newton's third law of motion. Ignition ensures that the propellant burns efficiently and consistently, allowing the rocket to achieve the necessary velocity to escape Earth's gravity.