A cookie is a little piece of data passed back and forth between the server and the client.
A cookie is a string that includes information in the form of a name-value pair separated by semicolons.
It remembers the user's information and preserves its state across all web pages.
It's vital to keep in mind that HTTP is a stateless protocol.
There is no connection between two consecutive HTTP requests sent to the server.
To put it another way, the server has no way of knowing if the two requests are from the same web browser.