Java technology is both a programming language and a platform.
The Java Programming Language
The Java programming language is a high-level language that can be characterized by all of the following buzzwords:
Simple | Architecture neutral |
Object oriented | Portable |
Distributed | High performance |
Interpreted | Multithreaded |
Robust | Dynamic |
Secure |
Each of the preceding buzzwords is explained in The Java Language Environment , a white paper written by James Gosling and Henry McGilton.
With most programming languages, you either compile or interpret a program so that you can run it on your computer. The Java programming language is unusual in that a program is both compiled and interpreted. With the compiler, first you translate a program into an intermediate language called Java bytecodes —the platform-independent codes interpreted by the interpreter on the Java platform. The interpreter parses and runs each Java bytecode instruction on the computer. Compilation happens just once; interpretation occurs each time the program is executed. The following figure illustrates how this works.