# Asynchronous programming with the Awaitable class

> Asynchronous programming in Unity with the .NET async and await keywords and Unity's own custom Awaitable class.

Asynchronous programming allows your code to perform long-running tasks without blocking the main thread. This allows your application to remain responsive and perform other tasks while it waits for an asynchronous task to complete.

Unity supports a simplified asynchronous programming model using the .NET [async](https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/keywords/async) key word and [await](https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/operators/await) operator.

Before reading about asynchronous programming in Unity, make sure you understand the fundamental elements of asynchronous programming in .NET. For important context, refer to [Asynchronous programming with async and await](https://learn.microsoft.com/en-us/dotnet/csharp/asynchronous-programming/) and [Task asynchronous programming model](https://learn.microsoft.com/en-us/dotnet/csharp/asynchronous-programming/task-asynchronous-programming-model).

| **Topic**                                                                                                                                  | **Description**                                                                                                                                  |
| ------------------------------------------------------------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------------------------------------------------------------------ |
| [Introduction to Awaitable](/engine/6000.3/manual/scripting/optimization/async-await-support/async-awaitable-introduction.md)              | Understand the key features of Unity's `Awaitable` and how it compares to both .NET `Task` and iterator-based coroutines.                        |
| [Awaitable completion and continuation](/engine/6000.3/manual/scripting/optimization/async-await-support/async-awaitable-continuations.md) | Understand how asynchronous code resumes on completion of an awaited task and how this affects the function and performance of your application. |
| [Awaitable code example reference](/engine/6000.3/manual/scripting/optimization/async-await-support/async-awaitable-examples.md)           | Solve common asynchronous programming problems with a reference of `Awaitable` code examples.                                                    |

## Additional resources

* [Awaitable API reference](/engine/6000.3/script-reference/unityengine/awaitable.md)
* [C# Job System](/engine/6000.3/manual/scripting/optimization/job-system.md)
* [Coroutines](/engine/6000.3/manual/scripting/object-oriented-development/coroutines-section/coroutines.md)