"A Linux server is a high-powered variant of the Linux open
source operating system that's designed to handle the more
demanding needs of business applications such as network and system
administration, database management and Web services.
"Linux servers are frequently selected over other server
operating systems for their stability, security and flexibility
advantages. Leading Linux server operating systems include CentOS,
Debian, Ubuntu Server, Slackware and Gentoo.
"See Linux and operating system terms in Webopedia, and learn
more about Open Source in Webopedia's 'Did You Know...?"