---
title: QualityOfService
framework: foundation
role: symbol
role_heading: Enumeration
path: foundation/qualityofservice
---

# QualityOfService

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

## Declaration

```swift
enum QualityOfService
```

## Overview

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

- [QualityOfService.userInteractive](foundation/qualityofservice/userinteractive.md)
- [QualityOfService.userInitiated](foundation/qualityofservice/userinitiated.md)
- [QualityOfService.utility](foundation/qualityofservice/utility.md)
- [QualityOfService.background](foundation/qualityofservice/background.md)
- [QualityOfService.default](foundation/qualityofservice/default.md)

### Initializers

- [init(rawValue:)](foundation/qualityofservice/init(rawvalue:).md)

## Relationships

### Conforms To

- [BitwiseCopyable](swift/bitwisecopyable.md)
- [Equatable](swift/equatable.md)
- [Hashable](swift/hashable.md)
- [RawRepresentable](swift/rawrepresentable.md)
- [Sendable](swift/sendable.md)
- [SendableMetatype](swift/sendablemetatype.md)

## See Also

### Constants

- [Operation.QueuePriority](foundation/operation/queuepriority-swift.enum.md)