Transitioning from a MySQL relational database to a schema-less NoSQL database like Couchbase is a significant shift but manageable with the right understanding of key differences. MySQL operates with structured tables, rows, and columns, while Couchbase uses JSON objects and arrays, allowing more flexibility in data storage without the constraints of a structured schema. In Couchbase, data relationships can be maintained through referring documents or embedding documents, offering versatility compared to the traditional relational model. Querying data in Couchbase with its N1QL language is similar to MySQL's SQL, enabling familiar operations like joins, albeit with differences like using bucket names instead of tables. Development tools and practices also differ, with Couchbase using its Java SDK rather than JDBC, and offering tools like CBQ and Query Workbench for interaction. Data migration can be facilitated by tools converting MySQL rows to Couchbase JSON documents, making the transition smoother. Despite these differences, Couchbase provides a flexible alternative for data storage and querying, maintaining some relational model aspects while offering expanded data handling capabilities.