什么是Java？

什么是Java？What Is Java?(中文5000字,英文)
在讨论Java时，区分Java编程语言，Java虚拟机和Java平台是很重要的。 Java编程语言是编写Java应用程序，applet，servlet和组成部分的语言。 编译Java程序时，会将其转换为字节代码，这些字节代码是称为Java虚拟机（也称为Java VM或JVM）的CPU结构的便携式机器语言。 JVM可以直接在硬件中实现，但通常以解释和执行字节代码的软件程序的形式实现。
Java平台不同于Java语言和Java VM。 Java平台是每个Java安装中存在的预定义Java类集; 这些类可供所有Java程序使用。 Java平台有时也称为Java运行环境或核心Java API（应用程序编程接口）。 Java平台可以使用可选包（以前称为标准扩展）进行扩展。 这些API存在于某些Java安装中，但不保证在所有安装中都存在。

What Is Java?
In discussing Java, it is important to distinguish between the Java programming language, the Java Virtual Machine, and the Java platform. The Java programming language is the language in which Java applications, applets, servlets, and components are written. When a Java program is compiled, it is converted to byte codes that are the portable machine language of a CPU architecture known as the Java Virtual Machine (also called the Java VM or JVM). The JVM can be implemented directly in hardware, but it is usually implemented in the form of a software program that interprets and executes byte codes.
The Java platform is distinct from both the Java language and Java VM. The Java platform is the predefined set of Java classes that exist on every Java installation; these classes are available for use by all Java programs. The Java platform is also sometimes referred to as the Java runtime environment or the core Java APIs (application programming interfaces). The Java platform can be extended with optional packages (formerly called standard extensions). These APIs exist in some Java installations but are not guaranteed to exist in all installations.