The text contrasts relational databases with NoSQL databases, specifically focusing on Couchbase, highlighting both similarities and differences in their structures and functionalities. In relational databases, data is organized into tables with rows and columns, while Couchbase uses a flexible document-based approach with JSON documents, allowing for a dynamic schema that can be easily modified. The document explains that Couchbase's Sub Document API enables operations on individual JSON fields, similar to manipulating specific columns in relational databases. Couchbase employs a query language called N1QL, a SQL superset, which allows for operations like JOINs using Buckets instead of tables. The text also discusses the differences in security approaches, noting that Couchbase manages permissions at the Bucket level, requiring some security logic to be handled at the application level, a shift from the column-level security of relational databases. The author concludes by inviting discussion on the implications of these differences, particularly regarding the location of application logic.