Web Server
A web server is a set of programs installed on a computer connected to
Internet or intranet and interacts with the client through a web browser and
delivers the web pages to the client. Apache and Microsoft's Internet
Information Server (IIS) are two leading web servers. In the case of java
language, a web server is used to support Servlet and JSP web components. A web
server does not provide support for EJB component. Web server accepts HTTP
requests from the client and provides HTTP response to the client. Usually they
also have the capability to collect the information about client requests and
server responses to the log files. Some web servers also have the features like
Authentication, HTTPS support, Content compression, Virtual hosting, Bandwidth
throttling etc.
Read more at:
http:/www.roseindia.net/servlets/IntroductionToWebServer.shtml