There are many editions of SDK, including:
Micro Edition (ME) for developers of applications for mobile or other devices with limited resources.
Standard Edition (SE) for developers of conventional desktop applications.
Enterprise Edition (EE) for developers of enterprise-wide applications.
Developers new to Java usually start with SE and then graduate either to ME or EE depending upon their interest/needs.
Home page for Java SE is:
http://java.sun.com/javaseIf you're installing on Linux, would it not be better to let your distribution's package manager sort out the installation?