The component of the universe that gives off light and has gravity is stars.

Here's why:

* Light: Stars are giant balls of hot gas, primarily hydrogen and helium. The intense heat and pressure at their cores cause nuclear fusion reactions, releasing enormous amounts of energy in the form of light and heat.

* Gravity: Stars have a strong gravitational pull due to their massive size. This gravity holds the star together and is what drives the nuclear fusion reactions in their cores.

While other celestial objects like planets and galaxies also have gravity, they don't produce their own light. Planets reflect light from stars, and galaxies are collections of stars, gas, and dust that emit light due to the stars within them.