My understanding of Cache-Control: no-cache is that it always asks the server to validate the cache.
I understand that "ETag" is used for validation in this case, how is this different from the client requesting validation using the "If-None-Match" header?
Here are the references I've seen https://medium.com/pixelpoint/best-practices-for-cache-control-settings-for-your-website-ff262b38c5a2