Updated on 01/28/2016
Wikipedia gives the following definition: "An HTTP cookie (also called web cookie, Internet cookie, browser cookie or simply cookie), is a small piece of data sent from a website and stored in the user's web browser while the user is browsing it. Every time the user loads the website, the browser sends the cookie back to the server to notify the user's previous activity. Cookies were designed to be a reliable mechanism for websites to remember stateful information (such as items added in the shopping cart in an online store) or to record the user's browsing activity (including clicking particular buttons, logging in, or recording which pages were visited in the past). Cookies can also store passwords and form content a user has previously entered, such as a credit card number or an address. (...) Other kinds of cookies perform essential functions in the modern web. Perhaps most importantly, authentication cookies are the most common method used by web servers to know whether the user is logged in or not, and which account they are logged in with. Without such a mechanism, the site would not know whether to send a page containing sensitive information, or require the user to authenticate themselves by logging in. The security of an authentication cookie generally depends on the security of the issuing website and the user's web browser, and on whether the cookie data is encrypted. Security vulnerabilities may allow a cookie's data to be read by a hacker, used to gain access to user data, or used to gain access (with the user's credentials) to the website to which the cookie belongs."
It appears from this definition that a cookie is not dangerous in itself. It is not a virus or an other computer program that can infect your computer. A cookie is a simple text file that stores some information used by the sites you browse.
However, cookies can pose a risk to your privacy. And the information they contain could be used by malicious individuals.
By deleting cookies set by our site, you may lose the contents of your shopping basket or some settings. However, blocking cookies might prevent you from using all or parts of our site.
If you would like to delete or block cookies, you may find the necessary information on your browser's Help menu or on Internet.