1. 沙发数据库：
Apache CouchDB 是一个开源的面向文档的 NoSQL 数据库，它使用多种格式和协议来存储、传输和处理其数据，它使用 JSON 存储数据，使用 MapReduce 作为其查询语言的 JavaScript，以及用于 API 的 HTTP。它由 Apache 软件基金会开发，最初于 2005 年发布。它是用 Erlang 编写的。
2. Redis :
Redis 代表远程字典服务器，它是一个内存数据结构项目，实现了具有可选持久性的分布式内存键值数据库。 Redis 由 Redis 实验室开发，最初于 2009 年 5 月 10 日发布。它是用 ANSI 和 C 语言编写的。 Redis 提供内存效率、运行速度快、高可用性，并提供一些特性，如可调性、复制、集群等。
CouchDB 和 Redis 的区别：
| S.No. | COUCHDB | REDIS |
|---|---|---|
| 1. | It was developed by Apache Software Foundation and initially released in 2005. | It was developed by Redis labs and initially released on May 10, 2009. |
| 2. | It is written in Erlang. | It is written in ANSI and C languages. |
| 3. | The primary database model for CouchDB is Document Store. | The primary database model for Redis is Key-Value Store. |
| 4. | It supports secondary indexes via views only. | It supports secondary indexes with RediSearch module only. |
| 5. | In CouchDB, there is no predefined datatypes. | It supports predefined datatypes. |
| 6. | The Server-side scripting in CouchDB is through JavaScript. | The Server-side scripting in Redis is through Lua. |
| 7. | It supports Map Reduce method. | It does not support Map Reduce method. |
| 8. | It does not have in-memory capabilities. | It have in-memory capabilities. |
| 9. | It supports both Master-Slave Replication and Master-Master Replication. | It supports both Master-Slave Replication and Multi-Master Raeplication. |
| 10. | Server operating systems for CouchDB are Android, BSD, Linux, OS X, Solaris and Windows | Server operating systems for Redis are BDS, Linux, OS X and Windows. |
| 11. | Famous companies like Twinkl Educational Publishing, Merrill Corporation, ASOS.com Limited, Owler, Inc., etc use Redis. | Famous companies like Akamai Technologies, Hothead Games, Inc., GenCorp Technologies, Vivint Solar, etc uses CouchDB. |