What is couchbase?

Couchbase is a Server, also known as Membase, is an open-source, distributed (shared-nothing architecture) multi-model NoSQL document-oriented database software package that is optimized for interactive applications. These applications may serve many concurrent users by creating, storing, and retrieving, aggregating, manipulating and presenting data. And also, Couchbase Server is designed to provide easy-to-scale key-value or JSON document access with low latency and high sustained throughput. It is developed to be clustered from a single machine to very large-scale deployments spanning many machines. A version originally called Couchbase Lite was later marketed as Couchbase Mobile combined with other software.