What is the difference between defer and async?

Answer»

S.no	defer	async
1.	It downloads the FILE during the HTML parsing but executes the DATA after the parsing is completed.	It downloads the data during the HTML parsing, but it stops the parsing from EXECUTING the downloaded file.
2.	Defer is used when the script relies UPON another script.	Async is used if the script does not rely upon any SCRIPTS.

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