Definition
Async, short for asynchronous, refers to a method in web development that allows a browser to initiate and execute multiple tasks concurrently without waiting for each individual task to finish before starting the next one.
What is it?
In a synchronous process, each task must complete before the next begins, which can cause delays and slow page loading times. Asynchronous operations, on the other hand, enable the browser to handle several processes simultaneously. For instance, when loading JavaScript asynchronously, the script downloads in parallel with other page elements, ensuring that the rendering of HTML is not stalled. This means that while one task (such as fetching a script) is still in progress, the browser can proceed with loading other resources like images or stylesheets.
How is it used?
Web developers incorporate asynchronous techniques by using attributes like async or defer in script tags, as well as leveraging modern JavaScript constructs such as Promises and the async/await syntax. These methods allow multiple resource requests and data processing tasks to run in parallel, improving overall page performance and user experience. Asynchronous loading is especially beneficial for dynamic content and applications where rapid interactions and real-time data retrieval are critical, ensuring that users experience minimal delay when navigating the website.
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