The Flash player plays the application in the case of an SWF-formatted response.

如果返回的格式为 SWF， 则由 Flash 播放器播放应用程序。

youdao

For invisible Flash, this does not really matter—the "you need to install the latest version of Flash" SWF is also going to be invisible (well, a 1x1 pixel anyway).

对于不可见 Flash，这其实没什么影响 — “您需要安装最新版本 Flash” 的 SWF 其实也不可见（当然，也是 1x1 像素）。

youdao

Instead of .class or .jar files, Flash executes .SWF ("swiff") files, laid out in a publicly-documented format, just as .class files are.

Flash执行.SWF(读作"swiff")文件而不是.class或.jar文件，这种文件格式也像.class文件一样是公开的。

youdao