Understanding Java

Basic Java Concepts

• Java is a full computer language. It is roughly comparable to C++ with some simplifications and improvements.
• Java is interpreted. A web browser, applet viewer or java interpreter functions as a "virtual machine". Java is not Javascript
• Source code (*.java) is compiled into "virtual machine" code (*.class). The .class files are compressed, binary files, which are interpreted.
• Because Java is interpreted, it is a cross-platform language. The same Java program will run on any system which implements the virtual machine. At present, Netscape provides Java support for Windows 95 and NT, Macintosh, Solaris, Irix, HP-UX, and linux. IBM WebExplorer supports Java under OS/2, and has announced plans for Java support under AIX and Win 3.1. Oracle PowerBrowser 1.5 support Java.
• Because Java is interpreted, it is slow.
• Programs can be run as stand alone programs, or they can be "applets" embedded in web pages. Applets have very little access to the system resources on the client machine. As stand alone programs, Java programs have the same access as other programs.