An example of the difference between cookies and sessions in PHP

session is temporary until the link is closed, and the cookie is persistent until the browser is emptied.

A session is where there are two places, the client and the server.

Cookies are only stored on the client side and will expire if the user's browser disables cookies.

The cookie exists on the client side (browser).

Session exists on the server side.

Specifically, the cookie mechanism uses a regimen that maintains state on the client side. It is a mechanism for storing the session state on the client's side, which requires the user to open the client's cookie support. The purpose of cookies is to solve the defect of the stateless HTTP protocol.

The session mechanism is a solution that maintains state between the client and the server. At the same time, we also see that since the server-side state-keeping scheme also needs to save an identity on the client, the session mechanism may need to use the cookie mechanism to achieve the purpose of saving the identity. Sessions, on the other hand, provide a convenient way to manage global variables.

Session is for each user, the value of the variable is stored on the server, a sessionid is used to distinguish which user session variable, this value is returned to the server by the user's browser when visiting, when the customer disables cookies, this value may also be set to get to return to the server.

In terms of security: when you visit a site that uses a session and create a cookie on your own machine, it is recommended that the session mechanism on the server side is more secure. Because it doesn't arbitrarily read the information stored by the customer.

Orthodox cookie distribution is achieved by extending the HTTP protocol, where the server adds a special line of instructions to the HTTP response header to prompt the browser to generate the corresponding cookie as instructed

From a web server point of view, all HTTP requests are independent of previous requests. This means that every HTTP response is completely dependent on the information contained in the corresponding request.

The state management mechanism overcomes some of the limitations of HTTP and allows the web client and server to maintain the relationship between requests. The period during which this relationship is maintained is called a session.

Cookies are small pieces of text that are stored locally on the machine by the server and sent to the same server with each request.

The session mechanism is a server-side mechanism where the server uses a structure similar to a hash table (or perhaps a hash table) to store information.