See supported Java 8 System Configurations for information about supported platforms, operating systems, desktop managers, and browsers.
u, and sometimes it is preceded with an underbar, for example,
You can install a JRE archive binary in any location that you can write to. It will not displace the system version of the Java platform provided by the Oracle Solaris OS.
The .tar.gz archive file (also called a tarball) is a file that can be simultaneously uncompressed and extracted in one step.
gzip -dc jre-8u73-solaris-sparcv9.tar.gz | tar xf -
gzip -dc jre-8u73-solaris-x64.tar.gz | tar xf -
The JRE is installed in a directory called jre1.8.0_<version> in the current directory. For example, for the JRE 8 update 73 release, the directory is named jre1.8.0_73
The JRE documentation is a separate download. See http://www.oracle.com/technetwork/java/javase/downloads/index.html#docs.