This property specifies the expiration of HTML document content by returning the value to the browser in the HTML file header. The browser compares the value of this property with the current date to determine whether to display a cached page or to request an updated page from the server.
By default, Content Expiration is disabled and the browser always displays an updated page from the server.
If Content Expiration is enabled, The browser compares the value of this property with the current date to determine whether to display a cached page or to request an updated page from the server.
The Web content should expire after field allows you to specify a period of time after which the browser is forced to retrieve the content again from the server on any subsequent requests.