This week's book giveaway is in the Mac OS forum. We're giving away four copies of a choice of "Take Control of Upgrading to Yosemite" or "Take Control of Automating Your Mac" and have Joe Kissell on-line! See this thread for details.
Also, please use real words when posting to the forums. Abbreviations such as "bw" in place of "between" and "diff" rather than "difference" only serve to make your posts more difficult to read and less likely to generate useful responses.
Apache HTTP Server is a C based server product which by default serves static files only and provides a CGI backend: http://httpd.apache.org You can add web modules to let it serve dynamic files. A commonly used one is PHP, a C based hypertext processor.
Apache Tomcat is a Java based server product which contains a Java EE web container and thus is capable to serve JSP and Servlet: http://tomcat.apache.org