the principle of relativity

[eVulcanon]

Is the general theory of relativity based on the principle of general relativity？or the principle of equivalence, or both of them? And if both of them, which one is more important? Thx

[Julian M]

Is the general theory of relativity based on the principle of general relativity?

Um. Not sure about that bit, however, the equivalence principle - that in any sufficiently small reason a gravitational field is indistinguishable from acceleration - is pretty fundamental.

Here, the "sufficiently small region" takes care of eliminating the tidal forces that would allow you to distinguish the field from (linear) acceleration.

[diazona]

I don't know about any "principle of general relativity" other than the principle of equivalence...

...unless you're thinking about the principle of relativity, which underlies special relativity: that physical laws are the same in all inertial reference frames.

[eVulcanon]

thank u guys!

[Ich]

The "General" refers to the principle of general covariance. From Wikipedia:
The essential idea is that coordinates do not exist a priori in nature, but are only artifices used in describing nature, and hence should play no role in the formulation of fundamental physical laws.
That's an extension to special relativity, where physical laws look the same only in a special subset of coordinate systems - inertial frames.