Learn in the textbookDomain Names, DNS, and How the Web Works
DefinitionA cookie is a small piece of data that a web server leaves with the visitor's browser, or the mechanism that does this.
ExplanationThe next time the site is opened, the browser sends this data back, so the server can tell who is visiting. It is used for things like staying logged in and restoring display settings. Because the data sits in the browser on the PC used for viewing, it does not carry over to another PC.
AnalogyLike a dry cleaner's claim ticket: the customer keeps it, and showing it tells the shop whose items it is holding.
Memory hookPicture a cookie kept close at hand, and you will remember that the data sits on the user's side, not on the server.