The blog post discusses the use of the RETURNING keyword in N1QL queries for Couchbase, which allows the result set of a query to be returned after operations like updates. It provides a practical example using a .NET Core console project, where five documents are initially inserted into a Couchbase bucket with a "processed" field set to false. The example then demonstrates updating these documents to set the "processed" field to true while using the RETURNING keyword to retrieve the updated documents and their keys. The author emphasizes the convenience of RETURNING in simplifying operations and suggests experimenting with more complex updates, such as using the IS MISSING operator. The full source code is available on GitHub, and readers are encouraged to reach out with questions.