Java Script shares most of Java's expression syntax and basic control flow constructs. JavaScript is an interpreted scripting language, while Java compiles applications in a system of classes. The following table compares and contrasts JavaScript and Java. Compiled on server before execution on client. Code uses built-in, extensible objects, but no classes or inheritance.
Applets consist of object classes with inheritance.
Object references checked at run-time. Object references must exist at compile-time. Cannot write to hard disk. Cannot write to hard disk. Netscape Java Script Authoring guide.