Cookies are simple text files.
Cookies don’t search your computer for information. Cookies register the information you provide through your browser. When you enter personal information on a website, the cookies store your information, both for ease of use on your next visit, and for ad tracking.
Cookies only store the information you provide. A cookie cannot “grab” your email address. A cookie can store your email address on the website—if you have typed in your email address; a cookie stores all information you voluntarily give when you visit a website.
Cookies themselves contain very little information other than the URL of the website that created the cookie.
Because there is so little information, a cookie can’t be used to identify you by name or other personal information.