"JAVA language foundation, Web front-end, database, graphic design, web design, game design, e-commerce, new media marketing, network engineering, interactive design, mobile design, etc. Introduction to JAVA source program (. Java files in the basic course of Beida Jade Bird Java language-> Java; Java bytecode file (. Class file)->; The bytecode file is loaded into the java virtual machine (JVM) by the interpreter (java.exe)->; Byte code file (. Class) will be executed in the java virtual machine.