Yes gasoline is a byproduct of oil.
To make gasoline the oil is extracted from the ground and then the oil which is known as crude oil is then refined into gasoline.
Gasoline was also a byproduct of Kerosene years ago.
Gasoline is a volatile, flammable liquid that is refined from crude oil or petroleum that is extracted from the ground.
Gasoline is actually a liquid fuel.
The gasoline that you pump into your car or vehicles gas tank fills the gas tank with liquid fuel.
Then when the fuel pump sucks that gasoline up from the tank and sends it through the fuel injectors it gets burned off and it's the gas vapor of the gasoline that actually causes the explosion in the cylinders that make your vehicle go.
As your engine is running the spark from the spark plugs ignite the gasoline and create explosions which pushes the cylinders.
So gasoline is liquid but it's burned off as a gas or vapor in the engine.