Wikipedia tackles some incredibly complex topics, from computer engineering to astrophysics and from elements of the periodic table to the cast of characters in the Pokémon universe. But Wikipedia is also aimed at a general audience, so the concept of "understandability" is very important. This is described in a guideline titled in the imperative mood: "Make technical articles understandable".
General advice offered in the guideline includes: make sure at least the lead section is accessible to as many readers as possible, include examples to illustrate concepts, avoid omitting key information just because it is technical, avoid oversimplifications, avoid jargon, and use images where possible.
Sometimes, it just isn't possible to write accurately and accessibly at the same time, which is why a handful of "Introduction to…" articles exist. "General relativity" a bit over your head? "Introduction to general relativity" should be more your speed.