Microsoft SQL Server (or MSSQL) and PostgreSQL are two largely used relational databases. Although both of them share a number of core properties or traits, there are significant differences between PostgreSQL and Microsoft SQL Server.

The most prominent distinction between PostgreSQL and Microsoft SQL Server is that SQL Server is owned and licensed by Microsoft Corporation, while PostgreSQL is open source. Apart from this, there are various differences between the two databases when it comes to licensing and cost, SQL syntax and compliance, ease of use, available features, data types, security and performance, and many other aspects.

It becomes a very crucial decision for the companies or organizations that are thinking of switching from a commercial to an open-source database a very precise and deep information on the advantages of the two databases and possible trade-offs is required.

It is particularly observed that the Microsoft SQL Server has historically been more used within the applications or organizations that rely on other Microsoft Corporation products, but PostgreSQL has gained popularity to the top of the field not only because of the advantages of going open source but also because of its numerous features and a large community of the active developers and users.

Difference between PostgreSQL vs Microsoft SQL Server:

Aspect or Parameter	PostgreSQL Database	Microsoft SQL Server
Definition	PostgreSQL is an open-source object-relational database system based on SQL language combined with many new features that are capable of storing and scaling complicated workloads securely and efficiently.	For the primary use of E-commerce and for multiple data warehousing solutions, a Microsoft SQL server is used.
Developed	The management of PostgreSQL is handled by PostgreSQL Global Development Group.	The development of Microsoft SQL Server is done by the Microsoft Corporation.
Type of Software	PostgreSQL is an Open-source software that means the source code of the PostgreSQL database is freely available,	Microsoft SQL Server is a closed source software licensed by Microsoft Corporation.
Date of Initial Release	PostgreSQL was initially released in 1996.	Microsoft SQL Server was released on April 24, 1989.
Latest Stable Release	The latest stable version is released on 13 May 2021.	The latest stable version is released on 4 November 2019.
Latest Version	The latest version is 13.3.	The latest version is SQL Server 2019
Supported Platforms	PostgreSQL is supported by all the major Operating Systems consisting of, FreeBSD, Linux, Solaris, HP-UX, NetBSD, OpenBSD, Unix, OS X, and Windows.	Linux and Windows are the operating systems that are primarily supported by SQL servers.
Programming languages Supported	PostgreSQL supports numerous programming languages such as JavaScript (Node.js), Tcl, PHP, C++, .Net, Python, Java, Perl, and C.	SQL Server is compatible with all the major programming languages such as Ruby, JavaScript (Node.js), C++, C#, PHP, Java, Visual Basic, Python, PHP, R, and Go.
Features	The major characteristics or features of PostgreSQL: All the major features of SQL are supported by PostgreSQL. PostgreSQL is highly extensible in nature. PostgreSQL is very much compatible with Data Integrity. Several programming languages are supported by PostgreSQL. PostgreSQL can be downloaded freely. PostgreSQL is compatible with secondary indexes. The support of XML is also provided by PostgreSQL. PostgreSQL is highly reliable. PostgreSQL is compatible with all the major operating systems. With the data scheme, there is consistency.	The essential features of Microsoft SQL Server are as follow: Microsoft SQL Server is platform-independent. Microsoft SQL Server is case insensitive, SQL (SEQUEL) language compatible, and has a shared database. Microsoft SQL Server is highly scalable. Microsoft SQL Server provides both commands-based and GUI software for usage. The implementation is from the RDBMS requirement. It can be run either on a network of cloud servers or a single computer system.
Case sensitivity	PostgreSQL is case-sensitive.	Microsoft SQL Server is not case-sensitive.
Computed Columns	The functional indexes have also supported that work just like a view. And computed columns are not offered.	The views are chosen over computed columns and computed columns are offered.
In memory competences	Memory capabilities are absent in PostgreSQL.	Microsoft SQL Server comes with memory capabilities.
Replication	The master-slave replication is supported by PostgreSQL.	Replications like transactional, log shipping, merge, snapshot, and mirroring are supported by Microsoft SQL Server but depend on the SQL-Server Edition.

So, with the help of this article, we can easily differentiate between PostgreSQL and Microsoft SQL Server.