译文大部分参照 docsChina ECMAScript 2018 译文。
A web browser provides an ECMAScript host environment for client-side computation including, for instance, objects that represent windows, menus, pop-ups, dialog boxes, text areas, anchors, frames, history, cookies, and input/output.
web 浏览器提供用于客户端计算的 ECMAScript 宿主环境，包括如代表窗口，菜单，弹出窗口，对话框，文本域，锚点，框架，历史记录，cookies以及输入/输出的实例对象。
Further, the host environment provides a means to attach scripting code to events such as change of focus, page and image loading, unloading, error and abort, selection, form submission, and mouse actions.
此外，宿主环境还提供了脚本代码处理如焦点改变、页面和图片的加载、卸载、错误和中断，选择，表单提交和鼠标交互等等事件的能力。
Scripting code appears within the HTML and the displayed page is a combination of user interface elements and fixed and computed text and images.
通过 HTML 中的脚本代码组合用户接口元素，固定及计算文本，图片来显示页面。
The scripting code is reactive to user interaction, and there is no need for a main program.
脚本代码不需要一个主程序即可对用户交互进行响应。
A web server provides a different host environment for server-side computation including objects representing requests, clients, and files; and mechanisms to lock and share data.
Web 服务器为服务器端提供了一个不同的主机环境，包括代表请求，客户端和文件的对象；以及锁定和共享数据的机制。译文存疑
By using browser-side and server-side scripting together, it is possible to distribute computation between the client and server while providing a customized user interface for a Web-based application.
为基于 Web 的应用程序提供一个定制的用户界面，通过浏览器端脚本及服务端脚本的配合使用，可以在客户端和服务端之间进行分布式计算。
Each Web browser and server that supports ECMAScript supplies its own host environment, completing the ECMAScript execution environment.
支持 ECMAScript 的 WEB 浏览器和服务器都将它们自身的宿主环境作为 ECMAScript 的补充，以使得 ECMAScript 的执行环境变得完整。
