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# CGWindowLevel

A level assigned to a window by an application framework.

```
typealias CGWindowLevel = Int32
```

## Discussion

In macOS, application frameworks support the concept of multiple window levels (or layers). Window levels are assigned and managed by each individual framework.

Note that in an Aqua-compliant application, each document window exists in its own layer. As a result, windows created by different applications can be interleaved.

## Topics

### Window levels

[`CGWindowLevelKey`](/documentation/CoreGraphics/CGWindowLevelKey)

Keys that represent the standard window levels in macOS. Quartz includes these keys to support application frameworks like Cocoa. Applications do not need to use them directly.


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