In today's web development world, finding standalone web apps is challenging. However, we can find most of these web apps work with each other where the integrations happen either from the Front-end or Back-end. One of the oldest yet simple integration strategies is using iFrames when examining these integrations.
The < iframe > element has a somewhat convoluted history; introduced by Microsoft around 1997 and supported in early versions of Internet Explorer, it was incorporated into HTML 4.0, banished from XHTML, and reintroduced in HTML5.