Couchbase is an open source, distributed NoSQL document-oriented database engine that is highly scalable, provides high availability and requires a simple administration. You can use Couchbase to store large amounts of data spread across data centers or when your applications require high write access speed.
Couchbase uses JSON documents, which has a self-explanatory format and proficient in representing various structures and relationships.
In Couchbase, documents are similar to rows in a relational table. Each row is uniquely identified by a row key. The column name uniquely identifies each column in the column family. The number of columns in each row can vary, and client applications can determine the number of columns in each row.
For example, in a relational data mode for an online flight booking application, you can use three separate tables for flights, schedules and airlines. This allows you to search for flights by dates. However, in Couchbase the document model is a single route object that embeds an array of schedules for all the flights in between the two airports. So, each route document is limited to itself. One request to a single Couchbase node give you access to all the information required to complete the booking.