Learning goals ：

master cookie and session The difference between

Learning content ：

        1.Cookie The data is saved on the client side ,Session Data is saved on the server side .
        2.Session yes The storage space of a server maintained by the server , When the user connects to the server , The server will generate a unique SessionID. Use this SessionID Access the server-side... For the identifier Session Storage space . and SessionID This data is saved to the client , use Cookie The saved . This process , Without developer intervention , So once the client is disabled Cookie, that Session It's going to fail .
        3.Cookie It belongs to Session A kind of object . But it's different .Cookie Will not occupy server resources , Is there client memory or Cookie In the text file . and Session It will occupy the server resources . therefore , Try not to use Session, While using Cookies.
however Cookie Full visibility of information and ease of local editing , It often causes a lot of security problems .

Session It's reliable , But at present, many famous sites also use Cookie.