关于冷热启动的概念描述不对

苹果在 WWDC 的 [Optimizing App Startup Time](https://developer.apple.com/videos/play/wwdc2016/406/) 给出了定义
> So when you launch an app, we talk about warm and cold launches.And a warm launch is an app where the application is already in memory, either because it's been launched and quit previously, and it's still sitting in the discache in the kernel, or because you just copied it over.

> A cold launch is a launch where it's not in the discache. And a cold launch is generally the more important to measure.The reason a cold launch is more important to measure is that's when your user is launching an app after rebooting the phone, or for the first time in a long time, that's when you really want it to be instant.