What is Expires Headers ?
Expires headers are guide to browser from website that how long it can keep resources in it’s cache. Based on requirement of updating of any type of resources we can give different expiry time for resources. So Expire headers determine for browser that it needs to fetch new version of resources or use cached version.
Expires headers work as saviour for high content rich pages. It helps to bring down number of resources require for loading page and hence improve loading speed and optimize performance for websites. As now a days it common to use higher number of images, graphics and videos to make web pages. So, it is necessity to use expires headers to bring down number requests for complete page load by avoiding the loading of static resources.
Expires headers works as command to browsers that particular resource needs to loaded new or use from local browser cache. Based on expiry time mentioned in expires header of particular resource. (Check how expires headers works in more details)
Expire headers greatly affect time of loading of web-page and bring down it too very significant amount. But there is also some cons of using expires headers in website and should be use very carefully while working with dynamic and frequently changing resources. If not using carefully can break your website or create errors on website.
There are many ways to add expires headers. Base on requirements you can choose better way for your website. It helps a lot for regular users who visit website regularly.