"Java isn't just for web sites.
Java is a programming language that lets you do almost anything you can do with a traditional programming langauge like Fortran or C++.
However Java has learned from the mistakes of its predecessors. It is considerably cleaner and easier to use than those languages.
As a language Java is
Simple: Java has the bare bones functionality needed to implement its rich feature set.
It does not add lots of syntactic sugar or unnecessary features.
Object-Oriented: Almost everything in Java is either a class, a method or an object.
Only the most basic primitive operations and data types (int, for, while, etc.) are at a sub-object level.
Platform Independent: Java programs are compiled to a byte code format that can be read and run by interpreters
on many platforms including Windows 95, Windows NT, and Solaris 2.3 and later.
Safe: Java code can be executed in an environment that prohibits it from introducing viruses, deleting or modifying files,
or otherwise performing data destroying and computer crashing operations.
High Performance: Java can be compiled on the fly with a Just-In-Time compiler (JIT) to code that rivals C++ in speed.
Multi-Threaded: Java is inherently multi-threaded.
A single Java program can have many different things processing independently and continuously." (Elliotte Rusty Harold)