Async (asynchronous) programming is a way to have pieces of code that involve waiting (such as making a GET request to a remote web server, or database queries) run without blocking other parts of the code from executing.
Imagine you need the result of two functions,
foo() requires data from a web page or HTTP API, and
bar() needs data from MySQL.
Traditionally, the execution flow will look like this:
Async can lead to performance improvements by changing the flow to look like this instead:
Our async documentation provides more information about this feature.