What is Async Programming?

At its core, async programming allows your program to start an operation that may take some time and avoid blocking while it waits for that operation to complete.

This contrasts with synchronous programming, where execution waits for an operation to finish before continuing past that point.

Imagine you’re making an API call, a very common task in modern applications.

Your application sends a request across the network and then has to wait for a response. Even if that response takes only a fraction of a second, that’s a long time in computer terms.

The important thing is that your application isn’t necessarily doing useful computation during all that time. A lot of it is simply waiting for something external to happen.

This is where async programming shines. Rather than blocking an execution resource while waiting for the API call to complete, asynchronous execution can allow other work to make progress and then continue the original operation when its result becomes available.