Developers use different editions of the Java platform to create Java programs that run on desktop computers, web browsers, web servers, mobile information devices (such as feature phones), and embedded devices (such as television set-top boxes). Java Platform, Standard Edition (Java SE): The Java platform for developing applications, which are stand-alone programs that run on desktops. Java SE is also used to develop applets, which are programs that run in web browsers. Java Platform, Enterprise Edition (Java EE): The Java platform for developing enterprise-oriented applications and servlets, which are server programs that conform to Java EE’s Servlet API. Java EE is built on top of Java SE. Java Platform, Micro Edition (Java ME): The Java platform for developing MIDlets, which are programs that run on mobile information devices, and Xlets, which are programs that run on embedded devices.

如果我是你，我会安装Java SE SDK。安装完成后，请确保设置了JAVA_HOME环境变量，并将%JAVA_HOME%\bin dir添加到路径中。

是的，您应该从Java SE开始。Java EE适用于web应用程序，Java ME适用于移动应用程序——两者都是基于SE构建的。

根据Oracle的文档，实际上有四个Java平台:

Java平台标准版(Java SE) Java平台，企业版(Java EE) Java平台，微型版(javame) JavaFX

Java SE is for developing desktop applications and it is the foundation for developing in Java language. It consists of development tools, deployment technologies, and other class libraries and toolkits used in Java applications. Java EE is built on top of Java SE, and it is used for developing web applications and large-scale enterprise applications. Java ME is a subset of the Java SE. It provides an API and a small-footprint virtual machine for running Java applications on small devices. JavaFX is a platform for creating rich internet applications using a lightweight user-interface API. It is a recent addition to the family of Java platforms.

严格地说，这些平台是规范;它们是规范，而不是软件。 Java平台标准版开发工具包(JDK)是一个官方实现 的Java SE规范，由Oracle提供。还有其他实现，比如OpenJDK和IBM的J9。

Java新手可以下载适合自己平台和操作系统的JDK (Oracle的JDK可以下载) 在这里。)

Java SE(标准版)用于构建桌面应用程序。

Java ME (Micro Edition)适用于旧的移动设备。

Java EE(企业版)用于开发基于web的应用程序。

以下是api方面的一些差异

Java SE包含以下api和更多api

小应用程序 awt rmi jdbc 摇摆不定的 集合 xml绑定 JavaFX(合并到Java SE 8) Java 8集合流API Java 9活性流API Java 9 HTTP/2 API

Java EE包括以下api和更多api

servlet websocket java的脸 依赖注入 ejb 持久性 事务 jms 批处理api

Java ME包括以下api和更多api

无线消息传递 Java ME Web服务 安全和信任服务API 位置 移动XML API

希望这能有所帮助。