A cookie is information stored on your computer by a website you visit. Cookies often store your settings for a website, such as your preferred language or location. When you return to the site, your web browser sends back the cookies that belong to the site. This allows the site to present you with information customized to fit your needs.
Cookies can store a wide range of information, including personally identifiable information (such as your name, home address, email address, or telephone number). However, this information can only be stored if you provide it - websites cannot gain access to information you didn't provide to them, and they can't access other files on your computer.