Extensions – also known as { -brand-name-firefox } Add-ons – are extra features you can download and install to add more functionality and tools to your browser. Add-ons allow you to customize your { -brand-name-firefox } browser and enhance the way you use the web.
扩展（也称 { -brand-name-firefox } 附加组件）可为浏览器增加额外功能和工具。使用附加组件可以定制您的 { -brand-name-firefox } 浏览器，提升上网体验。