Cookies are small files of data that are kept by your browser to be used at a later data, they are sometimes described as browser or web cookies.
When you re-visit the same site using an identical set of circumstances as in computer and browser (such as Firefox, Safari or Internet Explorer) the information stored by the cookie makes the surfing experiences quicker and more convenient.
Cookies are completely harmless, do not hold sensitive information such as personal details like names, addresses, email adresses or telephone numbers and do not carry viruses or trojans. Cookies are commonplace by virtual websites that exist
New laws were introduced recently that forces website owner to disclose the fact that coolies are present and give you the user the option to not let your browser install the cookies or visit the website.