Microsoft IIS (Internet Information Services) is a web server software created by Microsoft for hosting websites and applications on the Windows operating system. It provides a platform for serving web content, managing web applications, and supporting various protocols like HTTP, HTTPS, FTP, and more. IIS is known for its user-friendly interface, which allows administrators to easily configure settings, manage security, and monitor performance. It supports various programming languages, including ASP.NET, making it a popular choice for developers building dynamic web applications.