Java EE (Java Enterprise Edition) General Discussion

First off I probably should apologize in advance because my problem might be an eclipse config issue.

I created a simple servlet and I tried to include a jstl library import javax.servlet.jsp.jstl.sql.Result;. It compiled cleanly but, when I ran the application (through a browser accessing tomcat through eclipse) I was getting this error...

The absolute uri: http://java.sun.com/jsp/jstl/core cannot be resolved in either web.xml or the jar files deployed with this application

I eventually found out what was wrong but I don't understand why it was wrong and that's my question. Originally I had jstl.jar and standard.jar in the projectHome/lib directory. When I moved those 2 files to the projectHome]/WEB-INF/lib directory, however, things ran correctly. Is this a setting somewhere within my tomcat config on eclipse perhaps? Or can someone point me in the right direction about this issue in general?

Thanks in advance!