"simple, object-oriented, network-savvy, interpreted, robust, secure, architecture-neutral, portable, high-performance, multithreaded, and dynamic language". 

In detail, this means the following:

• Simple: Java can be programmed easily without esoteric training. It omits many rarely used and confusing features from C++, but still allows programmers who are familiar with C++ to grasp the concepts of Java programming with ease.
• Object oriented: Object oriented programming allows software components to be reused. Programmers are allowed to focus on the data in the application and methods that manipulate that data, rather than thinking strictly in terms of procedures.
• Network-savvy: Java is compatible with a variety of TCP/IP (Transmission Control Protocol/Internet Protocol) types such as HTTP (Hypertext Transport Protocol) and FTP (File Transport Protocol) which makes establishing network connections much easier than with C or C++.
• Interpreted: The Java compiler allows the files to be run on any machine that can run a Java-enabled browser. Java code can be written independent of platform because the Java compiler generates byte-codes rather than machine code.
• Robust: In software development, the word "robust" means that the software does not break easily. In comparison to C and C++, Java places more restrictions on the programmer, such as lack of pointer support, which increases the chances of a program running smoothly.
• Secure: Security is an important issue for Java programmers because Java is designed to work in Networked environments. Java lets users write virus-free systems that are authenticated with encryption techniques. The lack of pointers keeps programmers from forging to memory, which eliminates the possibility of memory overwrites and data corruption.
• Architecture-neutral: The Java compiler creates code that is intended for use with a Java-enabled browser installed on a network. This browser may be running on any platform such as Windows 95, Windows NT, Macs and Unix workstations. To enable Java applications the compiler generates an architecture-neutral object file format which is executable on many processors.
• Portable: Simplified arithmetic operation ensures that the Java source code will run the same on different platforms.
• High-performance: Because Java bytecodes are interpreted across different platforms, the performance sometimes suffers compared with direct compilation and execution on a particular hardware platform. Java compilers include an option to translate into machine code for that particular platform. While Java is defined as both an interpreted and a compiled language, it is not as fast as a strictly compiled language such as C. However, it is adequate to run applications where there is much time spent waiting on user interface, which is found on most Web pages.
• Multithreaded: Java allows applications where several things can be happening at once. This allows for support of real-time, interactive behavior, which is important for GUI (Graphical User Interface) based applications such as Web browsers, where you can be listening to an audio clip while you are scrolling a page, or downloading another image in the background.
• Dynamic: Java was designed to adapt to an evolving environment. It does not require recompiling after parent classes are changed thus allows new variables to have no effect on dependent class objects. The run time class definitions in Java allow the programmer to dynamically link classes into a running system.