How Cookies Work
Browsers visit websites. Websites deliver web pages.
Browsers can keep track of individual websites they have visited and even keep certain information handy for afterward.
Websites can not keep track of individual browsers without some help.
Browsers identify themselves to websites. But as a class, not individually.
Different brands and versions of browsers provide different identification. But all browsers of the same brand and version provide the same identification to all websites they visit.
For example, as they surf from page to page and site to site, all Firefox version such and such browsers provide the same identification as all other Firefox version such and such browsers.
Cookies were invented so websites could keep track of things individual browsers did and to be able to recognize the return of specific browsers.
In essence, the website puts together an information packet for the browser to keep (the cookie). The browser gives the cookie back when it returns — so long as the cookie has not expired.
The information the website gives to the browser (the cookie):
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Identifies the browser. Only this individual browser has this individual cookie.
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Contains information the website can use. As examples, the cookie might contain the number of pages visited, the time of the last visit, or complete shopping cart contents.
Browsers control whether or not they will accept cookies in general and can exempt certain websites. Browsers can expire a cookie at times other than the website requested.
You are in control of the browser and you can cause the browser to dump (delete) certain cookies or even all cookies.
The way cookies work is that browsers accept them (information packets) from websites and then give them back when they visit the site in the future.
The website can use the content of the cookie information pack the browser returns for continuing a discussion or interaction that was dropped when the browser left. It can use the cookie for statistical information. Actually, it can use the cookie for anything it is programmed to use it for.
Cookies don't do anything. They're just information packets the website gives to browsers to hold onto. And browsers give them back when they visit the site in the future.
Will Bontrager
