You may be familiar with the theory of relativity. When you say special relativity, this means that there are different physical phenomena that may occur even with the absence of gravity. When you say general relativity, this is a bit different because the main goal of this is to make sure that the different laws of gravitation have been explained and that the different forces of nature are related to this.
When you say special relativity, you also need to focus on those that are moving at a constant pace or at a constant velocity. For general relativity, you need to take into account acceleration too.