Apache CouchDB由 Apache Software Foundation 开发，最初于 2005 年发布。CouchDB 是用 Erlang 编写的。它是一个开源数据库，使用不同的格式和协议来存储、传输和处理其数据。 Apache CouchDB 使用 JSON 来存储数据，使用 MapReduce 作为其查询语言的 JavaScript。文档是 CouchDB 中的主要数据单元，它们还包括元数据。文档字段被唯一命名并包含不同类型的值，并且对文本大小或元素数量没有设置限制。
MongoDB 是面向文档的，不需要数据的行列格式。它提供了高性能并且本质上是动态的，我们不需要像在传统 RDBMS 中那样预定义模式。 MongoDB 以 JSON 格式存储数据，允许您以您想要的任何形式发送数据。它是跨平台数据库，几乎适用于所有平台，如 Windows、Linux 等。
CouchDB 和 MongoDB 的区别
在本节中，我们将讨论 CouchDB 和 MongoDB 这两个数据库之间的差异。
| S.NO | CouchDB | MongoDB |
|---|---|---|
| 1 | Datastores in JSON format. | Datastores in BSON format. |
| 2 | The database contains documents. | The database contains collections. |
| 3 | It favors availability. | It favors consistency. |
| 4 | It is written in Erlang. | It is written in C++. |
| 5 | It is eventually consistent. | It is strongly consistent. |
| 6 | MongoDB is faster than CouchDB. | MongoDB provides faster read speeds. |
| 7 | It follows the Map/Reduce query method. | It follows Map/Reduce creating a collection and object-based query language. |
| 8 | It uses HTTP/REST-based interface. | It uses a TCP/IP based interface. |
| 9 | CouchDB provides support for Mobile Devices. It can run on Apple iOS and Android devices. |
MongoDB provides no mobile support. |
| 10 | CouchDB offers master-master and master-slave replication. | MongoDB offers master-slave replication. |
| 11 | CouchDB is not suitable for a rapidly growing database where the structure is not clearly defined from the beginning. | MongoDB is an apt choice for a rapidly growing database. |
| 12 | CouchDB uses map-reduce functions and it will difficult for users with a traditional SQL learning experience. | MongoDB is easier to learn as it is closest in syntax to SQL. |