Full Text Search (FTS) is introduced as a developer preview in Couchbase 4.5, offering a glimpse into future capabilities not yet ready for production use. Unlike basic SQL searches, FTS provides a more sophisticated, language-aware search experience, ranking results by relevance. The blog details the process of setting up a Full Text Search index on the travel-sample data bucket within Couchbase, including configuring type mappings to restrict searches to specific document types, such as "landmark." It also covers executing FTS queries in the Couchbase Console and ASP.NET applications. In ASP.NET, the author demonstrates using the Couchbase .NET SDK to perform searches, highlighting terms within search results. The blog emphasizes that FTS is currently a developer preview, inviting users to participate in its development by reviewing and providing feedback on the Full Text Search RFC on GitHub.