Definition of Internet information services

Microsoft Internet Information Services (IIS, formerly called Internet Information Server) is a set of Internet-based services for servers using Microsoft Windows. It is the world's second most popular web server in terms of overall websites, behind Apache HTTP Server. As of October 2007 it served 37.13% of all websites and 38.23% of all active websites according to Netcraft. The servers currently include FTP, SMTP, NNTP, and HTTP/HTTPS.