Hi . . .


What is different bitween IIS and Apache and Tomcat and Jboss and zeus ?

That's like asking about the differences between Windows, Linux, BSD and OS X. They're VERY different.

Apache is an open source web server. Used primarily for php stuff, but also for others (perl, python, etc). It's what's normally used to host most blogs and forums, as most are written in PHP, and LAMP hosting is dirt cheap.
IIS is windows' web/app server. Will handle everything Apache does, plus also ASP.NET and classic ASP stuff (only IIS can serve that basically). But as it requires windows which is not free unlike Linux, hosting costs more.
JBoss is one of many java application servers.
Zeus? Never even heard of it. Likely has a market share well under 1%...