Internet Information Server or IIS is a Microsoft-created, native modular web server application designed to support request methods of HTTP, HTTPS, FTP, FTPS, Simple Mail Transfer Protocol (SMTP) and Network News Transfer Protocol (NNTP). The power of IIS is that the modules—called extensions—that IIS server use to automate requests are customizably installed or removed for specific functionality. For example, HTTP modules will respond to information and requests sent in client headers, returning HTTP errors, and redirecting requests, where as compression modules will apply GZIP compression to transfer coding of static content, while security modules govern authentication requirements; Client Certificate Mapping, IP Security, URL authorization, and filtering requests (added in IIS 7.5):
https://docs.microsoft.com/en-us/iis/get-started/introduction-to-iis/iis-web-server-overview
IIS's content modules process requests for static files, for example, returning a default page when a client does not specify a resource in a request, and listing the contents of a directory, while caching modules and logging and diagnostics modules store and pass information and processing status to
HTTP.sys for logging, reporting events, and tracking requests in worker processes. Learn how to install IIS:
https://it.cornell.edu/managed-servers/install-windows-iis
A IIS engineer will be needed for troubleshooting many issues in Experience installing and troubleshooting problems on Win 9x, Win2K, WinXP, Vista, 7 and WinNT 4.0/Win2K/Win2003/2008 Server, for example: the anonymous user which was named "IUSR_{machinename}" in IIS 6.0 is a built-in account in Vista and future operating systems and named "IUSR" in IIS 7+.
IIS 5.0 and higher support the following authentication mechanisms:
- Basic access authentication
- Digest access authentication
- Integrated Windows Authentication
- NET Passport Authentication (not supported in Windows Server 2008 and above)