Difference between Couchbase and MS SQL Server

1. Couchbase : Couchbase Server is an open-source, distributed multi-model NoSQL document-oriented database software package that is optimized for interactive applications. It is also known as Membase. It was developed by Couchbase, Inc. and initially released on August 2010. 2. MS SQL Server : Microsoft SQL Server is a relational database management system (RDBMS) which is platform dependent and it is both GUI and command based software. It supports a wide variety of transaction processing, business intelligence and analytics applications in corporate IT environments. It was developed by Microsoft Corporation and initially released on April 24, 1989. It is written in C and C++ languages.
Difference between Couchbase and MS SQL Server :

S.NO.	Couchbase	Ms SQL Server
1.	Developed by Couchbase, Inc. and initially released on August 2010.	Developed by Microsoft Corporation and initially released on April 24, 1989.
2.	Couchbase is written in C++, Erlang, C and Go languages.	MS SQL server is written in C and C++.
3.	The license for Couchbase is open source.	The license for MS SQL Server is Commercial.
4.	The primary database model for Couchbase is Document Store.	The primary database model for MS SQL Server is Relational Database.
5.	The secondary database model for Couchbase is key-value store.	The secondary database model MS SQL Server is Document Store and Graph DBMS.
6.	Couchbase is Data Schema free.	In MS SQL Server the data schema is Fixed.
7.	There is no Foreign Keys in Couchbase.	MS SQL server supports Foreign Keys.
8.	Couchbase supports Map Reduce method.	MS SQL Server does not supports Map Reduce method.
9.	Couchbase provides Eventual Consistency and Immediate Consistency methods to ensure consistency in a distributed system.	MS SQL Server only provides Immediate Consistency method to ensure consistency in a distributed system.
10.	Server operating systems for Couchbase are Linux, OS X and Windows.	Server operating systems for MS SQL Server are Linux Windows.
11.	Famous companies like Lockwood Publishing, Code Weavers, MSLGROUP, The Doyle Group, etc uses Couchbase.	Famous companies like Citi, Bank of America, UPS, etc uses MS SQL Server.