Medium of light travel in space

What is the difference between space and vacuum?
Since light waves require a medium to travel, then what is the medium in space?

rekha1804 said:

Since light waves require a medium to travel,

They don't. Discovering that there's no evidence of a medium was a large part of the work that led to relativity theory.

rekha1804 said:

What is the difference between space and vacuum?

Empty space is a vacuum. Interstellar and intergalactic space are almost empty, but not quite.

rekha1804 said:

Since light waves require a medium to travel

This is a faulty assumption and you would do well to get rid of it.