Bing found these results
General relativity - Wikipedia
What is the theory of general relativity? | Space
Introduction to general relativity - Wikipedia
General relativity | Gravitational Waves, Spacetime & Cosmology
General Relativity | Physics | MIT OpenCourseWare
What Is The General Theory of Relativity? : ScienceAlert
General Relativity | Brilliant Math & Science Wiki
Theory of relativity - Wikipedia
Relativity | Definition, Equations, & Facts | Britannica
Relativity - Space-Time, Gravity, Physics | Britannica