Like the computer browser, in order to improve the speed of accessing web pages, the browser in the mobile phone will store the web pages (including pictures and cookie files) you have visited in the mobile phone in a cumulative and accelerated way. This storage space, we call it cache. In the future, every time we visit a website, we will search this directory first. If there is already visited content in it, we don't need to download it from the internet, but directly transfer it from the cache, which improves the speed of visiting the website. Definition of caching: Browser caching is to speed up browsing. The browser stores the recently requested document on the user's disk. When the visitor requests this page again, the browser can display the documents on the local disk, which can speed up the browsing of the page. This is one of the most difficult problems in website visit statistics. To put it simply: caching is similar to human memory, that is, it can accurately remember what just happened. Only on mobile phones. Generally speaking, caching allows you to quickly browse the web pages you have just visited, and it can also reduce online traffic. Note: a Cookie is a piece of text saved by the Web server on the user's hard disk. Cookie allow websites to save information on users' computers and retrieve it later. Information fragments are stored in the form of "name-value pairs". Cookie, also known as Cookies, is a technology that enables the website server to store a small amount of data in the client's hard disk or memory, or read data from the client's hard disk. Cookies are very small text files that are put on your hard disk by the Web server when you browse a website. It can record your user ID, password, the pages you visited, the time you stayed and other information. When you come to the website again, the website can read Cookies and get your relevant information, so you can take corresponding actions, such as displaying a welcome slogan on the page, or allowing you to log in directly without entering an ID or password. It can be regarded as your ID card in essence.