How do conventional rockets work?
An oxidizer is a type of chemical which a fuel requires to burn. Most types of burning on Earth use oxygen, which is prevalent in the atmosphere. However in space there is no atmosphere to provide oxygen or other oxidizers so rockets need to carry up their own oxidizers. Usually, they are carried in a different tank than the fuel and released in the proper proportion with the fuel when the rocket is fired.
What is a propellant?
How are rockets designed?
What is the difference between an ion engine and a conventional one?
How does propulsion work?
What are the types of rocket propulsion?
How do things burn?
How is rocket propulsion different from jet propulsion?
What are some rocket propellants?
What is a monopropellant?