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# QualityOfService

Constants that indicate the nature and importance of work to the system.

```
enum QualityOfService
```

## Overview

Work with higher quality of service classes receive more resources than work with lower quality of service classes whenever there’s resource contention.

## Topics

### Constants

[`NSQualityOfServiceUserInteractive`](/documentation/Foundation/QualityOfService/userInteractive)

[`NSQualityOfServiceUserInitiated`](/documentation/Foundation/QualityOfService/userInitiated)

[`NSQualityOfServiceUtility`](/documentation/Foundation/QualityOfService/utility)

[`NSQualityOfServiceBackground`](/documentation/Foundation/QualityOfService/background)

[`NSQualityOfServiceDefault`](/documentation/Foundation/QualityOfService/default)

## Relationships

### Conforms To

[`SendableMetatype`](/documentation/Swift/SendableMetatype)

[`BitwiseCopyable`](/documentation/Swift/BitwiseCopyable)

[`Sendable`](/documentation/Swift/Sendable)

[`RawRepresentable`](/documentation/Swift/RawRepresentable)

[`Hashable`](/documentation/Swift/Hashable)

[`Equatable`](/documentation/Swift/Equatable)

---

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