Why Use Async/Await Over Normal Threading or Tasks?

Yes, it is a syntactic sugar that makes dealing with threads much easier, it also makes the code easier to maintain, because the thread management is done by run-time. await release the thread immediately and allows that thread or another one to pick up where it left off, even if done on the main thread.

Like other abstractions, if you want complete control over the mechanisms under the covers, then you are still free to implement similar logic using thread signaling, etc.

If you are interested in seeing what async/await produces then you can use Reflector or ILSpy to decompile the generated code.

Read What does async & await generate? for a description of what C# 5.0 is doing on your behalf.

If await was just calling Task.Wait we wouldn't need special syntax and new APIs for that. The major difference is that async/await releases the current thread completely while waiting for completion. During an async IO there is no thread involved at all. The IO is just a small data structure inside of the kernel.

async/await uses callback-based waiting under the hood and makes all its nastiness (think of JavaScript callbacks...) go a way.

Note, that async does not just move the work to a background thread (in general). It releases all threads involved.

Comparing async and await with threads is like comparing apples and pipe wrenches. From 10,000 feet they may look similar, but they are very different solutions to very different problems.

async and await are all about asynchronous programming; specifically, allowing a method to pause itself while it's waiting for some operation. When the method pauses, it returns to its caller (usually returning a task, which is completed when the method completes).

I assume you're familiar with threading, which is about managing threads. The closest parallel to a thread in the async world is Task.Run, which starts executing some code on a background thread and returns a task which is completed when that code completes.

async and await were carefully designed to be thread-agnostic. So they work quite well in the UI thread of WPF/Win8/WinForms/Silverlight/WP apps, keeping the UI thread responsive without tying up thread pool resources. They also work quite well in multithreaded scenarios such as ASP.NET.

If you're looking for a good intro to async/await, I wrote up one on my blog which has links to additional recommended reading.