Back Forward Cache Explained
Back Forward Cache is a technique browsers use to instantly load a Web Page when the Back or Forward buttons on the browsers are pressed.
Back/Forward Cache is currently supported by all major browsers including Google Chrome, Mozilla Firefox, and Safari. According to Google Chrome's data, about 10% of all navigations on Desktop are either Back or Forward. This number goes all the way to 20% in the case of Mobile browsing.
By ensuring that your website is eligible for Back/Forward Cache, you can make a dramatic difference to the Page Speed and User Experience of your website.