What is a Cookie File/Folder?
Cookies are small, usually randomly encoded, text files that help your browser navigate through a particular website. The cookie file is generated by the site you’re browsing and is accepted and processed by your computer’s browser software. The cookie file is stored in your browser’s folder or subfolder.
Your browser accesses the cookie file again when you visit the website that created the cookie file. The browser uses the information stored in the cookie file to help ease your navigation of the website by letting you log in automatically or remembering settings you selected during your earlier visits to the website, among many other functions.
Any particular website cannot access information on your computer other than the cookie it set on your computer. The cookie is not executable code so it doesn’t have any “life” of its own other than being used by the website that created it. As explained above, such use is limited to helping your browser process the information located on the website.
Essentially this is the memory of your internet browser where you can find all your cookies stored in a format that facilitates easy retrieval by a browser.
What Cookies Do to Your PCs
Cookies are browser dependent and are essentially text files that contain information your browser saves on one of this folders for some websites that do send out cookies. By themselves, cookies pose no risk since they do not contain virus in any form nor do they spy on your PC content to compromise security. They are used to make online surfing faster and easier by make the sites you`ve visited remember who you are, like remembering you IP address or passwords, along with your own preferences such as when Amazon recommend a book or music CD similar to what you looked for in your last visit.
But this convenience feature of having cookies can be eagerly overused when some websites use them to track you across various websites often for analytical competition purposes and thus, record you surfing behavior. In gets a bit frightening when the companies that track you are those you have never dealt with and to whom you never gave your personal information.
Older browsers like Internet Explorer 5.x or Netscape 4.x offered a limited choice in managing cookies. They just completely allow or disallow cookies so you either benefit from them or not. They can also be set to prompt you for a YES or NO response in each attempt for a site to send one. Today, newer browsers from Internet Explorer, Firefox, and Opera allows better degree of control in selecting which sites can or cannot send cookies.
More informations: https://en.wikipedia.org/wiki/HTTP_cookie.