What are cookies and why do I need them to bank online?

Cookies are messages that a Web server sends to your browser to identify users and sometimes save login information. Some cookies remain on your hard drive until you delete them. Other cookies, like the ones we use for security purposes, are stored on your browser only while you’re on the site that issued them. Each time you perform a transaction or view a new page on our secure server, the message is sent back to the server to authenticate the request.