General Relativity is based on the idea that the presence of mass and energy curves spacetime, which in turn affects the motion of objects.

The Schwarzschild radius is the radius of the event horizon of a black hole, beyond which nothing, not even light, can escape.

Gravitational lensing is the bending of light around massive objects, such as stars and galaxies, due to the curvature of spacetime.

Gravitational waves are ripples in spacetime that are caused by the acceleration of massive objects.

Gravitational time dilation is the phenomenon where time slows down in a stronger gravitational field.

Gravitational redshift is the phenomenon where light is shifted towards longer wavelengths in a stronger gravitational field.

Gravitational precession is the phenomenon where the orbit of a planet around a star is not a perfect ellipse, but rather precesses, or wobbles, over time.

Frame dragging is the phenomenon where the rotation of a black hole drags spacetime around with it, causing objects to orbit the black hole in a spiral path.

Gravitational microlensing is the phenomenon where the gravitational field of a massive object can cause a star to appear to be brighter than it actually is.

Gravitational astrometry is the phenomenon where the gravitational field of a massive object can cause a star to appear to be in a different position than it actually is.

Gravitational Doppler shift is the phenomenon where the gravitational field of a massive object can cause a star to appear to be moving faster or slower than it actually is.

Gravitational color shift is the phenomenon where the gravitational field of a massive object can cause a star to appear to be redder or bluer than it actually is.

Gravitational mass shift is the phenomenon where the gravitational field of a massive object can cause a star to appear to be more massive than it actually is.

Gravitational age shift is the phenomenon where the gravitational field of a massive object can cause a star to appear to be younger or older than it actually is.

Gravitational luminosity shift is the phenomenon where the gravitational field of a massive object can cause a star to appear to be more or less luminous than it actually is.