While light itself has no mass, it is still influenced by the gravitational field of black holes. This is because gravity is not exclusively determined by mass but by the curvature of spacetime caused by mass and energy.
According to Einstein's theory of general relativity, massive objects like black holes can curve the fabric of spacetime around them. When light passes close to a black hole, it follows the curvature of spacetime and bends due to the gravitational pull of the black hole. This phenomenon is known as gravitational lensing.
In extreme cases, when light passes very close to a black hole, it can be captured by the intense gravitational field and fall into the black hole itself. The boundary beyond which light cannot escape is called the event horizon of the black hole. Once inside the event horizon, no information, including light, can escape from the black hole.
The bending of light by a black hole's gravity has been observed and confirmed through various astronomical observations. It is one of the significant predictions of general relativity and provides evidence for the existence and influence of black holes in the universe, even on massless particles like light.