What are the better fuels for spacecraft that often travel through the universe?

The source of power for a small car is gasoline or electricity, so what is the source of power for a spacecraft? I believe that many people have thought about this problem, after all, the spacecraft is sailing in the universe, if the power is not enough to sail, there is a possibility of crashing, then the spacecraft you have no use. That often in the universe shuttle spacecraft, with which fuel is better?

What is the best fuel for a spacecraft that travels through the universe?

We need to know that spacecraft and cars are different, because spacecraft need more power, if there is no more power to push, then the spacecraft is not able to run, so spacecraft can not use gasoline or electricity. The power of gasoline or electricity is also very insufficient to propel the spacecraft on the spacecraft to lift off or operate in the universe. I also made some inquiries on the Internet and found that previous spacecraft or rockets used liquid oxygen as fuel. Liquid oxygen is a more adequate fuel, when burning can release very much hydrogen, it can release a lot of heat. Besides liquid oxygen, most spacecraft nowadays use electric propulsion or high-pressure propulsion. And some of the smaller spacecraft use combustion batteries, and the larger ones come with booster rockets that are fueled by liquid oxygen or liquid hydrogen.

Spacecraft require a lot of fuel, and liquid oxygen provides a lot of heat.

I didn't know much about spacecraft before, but now I've searched the Internet and found that spacecraft need a lot of heat to operate, and if there's not enough heat, they can't operate at all. So the spacecraft needs very sufficient fuel, such as liquid oxygen or combustion batteries, so that the spacecraft can operate, and also enable mankind to obtain some mysteries from the universe, so as to explore more knowledge. And the spacecraft has a certain amount of fuel, if the fuel is burned out, then it is not able to continue to replenish.