Classpath - ext directory

[Gunjan Doshi]

Friends:
I know that this is not directly releated to Tomcat, but does affect it.

Config:
OS: Windows NT 4.0 Srv
JDK Directory: c:\jdk1.2.2
JRE: c:\program files\javasoft\jre1.2.2

When you put user jar files in 
C:\jdk1.2.2\jre\lib\ext
and
C:\Program Files\JavaSoft\JRE\1.2\lib\ext
Jar files get added to the classpath.

Question:
1. What role does the ext directory play
2. Do I need to put the jar files in both the ext directories above.

Thanks in advance
Gunjan