Xcode 8-为什么“项目和目标”设置可以选择不同的部署目标版本？

Question

Xcode 8.3.2 Here are the screenshots from the same test project.

1. Select "Project" you can choose the deployment target IOS version
   

2. Select "Target" you get another choice of deployment target version

I am probably missing something, but I don't understand the benefit of the 2 separate choices!
(I have shown them as different here, but in my real project I always set them the same).

Answer 1

A project can have multiple targets. It's possible that some of the targets could have a older or newer Deployment Target than the rest of the targets.

The project-level lets you set the most common Deployment Target used by most targets. You can then adjust a specific target to have a different Deployment Target if needed.

When you only have one target, it doesn't matter which you change, the project or the target.