What are Cookies?

A cookie is a small file, typically of letters and numbers, downloaded on to a device when the user accesses certain websites. Cookies are then sent back to originating website on each subsequent visit. Cookies are useful because they allow a website to recognise a user’s device.

Session and persistent cookies

Cookies can expire at the end of a browser session (from when a user opens the browser window to when they exit the browser) or they can be stored for longer.

Session cookies

allow websites to link the actions of a user during a browser session. They may be used for a variety of purposes such as remembering what a user has put in their shopping basket as they browse around a site. They could also be used for security when a user is accessing internet banking or to facilitate use of webmail. These session cookies expire after a browser session so would not be stored longer term.

Persistent cookies

are stored on a users’ device in between browser sessions which allows the preferences or actions of the user across a site (or in some cases across different websites) to be remembered. Persistent cookies may be used for a variety of purposes including remembering users’ preferences and choices when using a site or to target advertising.

First and third party cookies

Whether a cookie is ‘first’ or ‘third’ party refers to the website or domain placing the cookie. First party cookies in basic terms are cookies set by a website visited by the user - the website displayed in the URL window. Third party cookies are cookies that are set by a domain other than the one being visited by the user. If a user visits a website and a separate company sets a cookie through that website this would be a third party cookie.