The text discusses the introduction of SDL (Schema Definition Language) support in Apollo Android, a framework for building GraphQL APIs. The main reasons for adopting SDL include its conciseness, ease of reading and writing, and the ability to carry more information than introspection schemas. The author explains how to use SDL in Apollo Android, including transforming existing introspection schemas to SDL, downloading SDL schemas from introspection or Studio, and using tools like `convertApolloSchema` and `downloadApolloSchema`. The text concludes that while it's still early days for SDL support in Apollo Android, the benefits of using SDL have been demonstrated through its successful use in writing unit tests.