Look at the picture on the
Sun Java Certifications website. It shows you the certification paths.
If you're
SCJP certified, you can choose different directions:
Desktop Java:
SCJD - More about Java SE; desktop apps, Swing, client-server apps
Web applications:
SCWCD - About the web tier Java EE technologies (
servlets, JSPs, ...)
SCBCD - About the business tier Java EE technologies (EJBs, ...)
SCDJWS - About web services
Mobile:
SCMAD - About Java ME
My personal opinion is that if you want to go in the web applications direction, it would be most logical to first look at SCWCD, and after that at SCBCD and/or SCDJWS.