I've adjusted the expiration tags on many of the files of my website (with .htaccess). As you know, this can create a tiny problem of a users browser not showing the most updated version of a website until the cached version of the file expires.
I began looking for a way to avoid this and then I remembered using CloudFlare some time ago. CloudFlare makes it possible to adjust these same tags but it also has a purge feature. What is 'purge' doing?