Full Title and Meme
Cookies are chunks of data that are placed in a user agent (typically a browser) that allow a web site to maintain continuing of user experience.
The problem with cookies is the power that it gives the web site, or a widget hosted on the web site to track the user.
Starting from the entry on HTTP Cookie in Wikipedia we find that Lou Montulli of Netscape added then to the Mosaic browser to enable an ecommerce application that was requested by Vint Cert, inter alia in 1994. The point was to save state on the client computer rather in the browser.