A cookie is a data file stored on your computer by websites / web servers you visit directly or indirectly. While some features of cookies make your Internet browsing experience more efficient and user-friendly, some other features might infringe on your privacy. So, it is best to delete cookies frequently / regularly from your computer.
Cookies that persist even after you close the browser and shut down your computer are known as persistent cookies. These cookies track your Internet usage more persistently, over a longer period of time. They have an expiry date which can be a few days or few months or few years from today. Unless you delete these cookies regularly, your Internet usage pattern (in other words, your privacy) will be gathered by the software that placed the said cookies for later commercial use.
Cookies that do not persist after you close your browser and shut down your computer are known as session cookies. These cookies are placed by the web sites you visit to track your usage patterns for your current web browsing session, and also to help these web sites to serve you data / information more efficiently, should you stay on the web site for a while. These cookies are less dangerous than session cookies in terms of compromising your privacy; however it is best to delete these cookies regularly as well.
If you use Apple Safari, Resetting Safari deletes your browsing history and all cookies. If you use Mozilla Firefox on Apple Mac OS X, Resetting Private Data automatically does not delete the cookies, you will have to go to Preferences and explicitly view and/or delete the cookies. If you use IE on Microsoft Windows, you have to go to Internet Options and click on the Delete All option / button to delete browsing history, temporary files, stored passwords, and all cookies. If you use Mozilla Firefox on Microsoft Windows, Resetting Private Data deletes your browsing history and all cookies.
