The space between two objects in space is generally referred to as "interstellar space" or "interplanetary space," depending on the context.
Interstellar space refers to the vast regions of space between star systems within a galaxy. It is the space that contains stars, nebulae, and other cosmic structures. Interstellar space is characterized by low density, with sparse distribution of gas, dust, and other matter.
Interplanetary space, on the other hand, specifically refers to the space between planets within a star system, such as our solar system. It encompasses the regions traversed by planets, moons, asteroids, comets, and other objects in orbit around a star.
These terms are used to describe the vast expanse of space that separates celestial objects, highlighting the vast distances and relatively empty nature of the space between them.