The HTTP request header Pragma: no-cache performs the same function as which other header?

The HTTP request header "Pragma: no-cache" is an older mechanism used to instruct caches to not serve cached content but rather to validate the information before serving it to ensure that the most recent version is retrieved. The "Cache-Control: no-cache" header serves a similar purpose but is a more modern and recommended way to achieve this functionality. When "Cache-Control: no-cache" is used, it specifically directs caches to revalidate the resource before using a cached copy, ensuring the client receives an up-to-date response.

Both headers effectively communicate the same intention regarding caching behavior, with "Cache-Control: no-cache" being the standard set by more recent HTTP specifications. This makes the relationship between the two headers significant for proper caching behavior in web applications. The distinction lies in their contexts of use and acceptance in various environments, with "Cache-Control" being preferred in contemporary web development for its clarity and alignment with current standards.