A cookie is a small text file that is automatically sent to your device where it is stored by your web browser. The cookie stores a unique identifier (a string of random characters) so that your browser can be distinguished from others, and are often used to link your browser to databases that hold data about your usage and inferred interests, along with other data such as your IP address. They are used for various functions - from enabling the website to work, by recognizing the same user as they navigate from one page to another; to analyzing what content is viewed and is popular, through to personalizing content based on browsing behavior and interests.
Cookies may be stored by the website you are visiting (a “first party cookie”) or by a technology provider, such as an analytics company, advertising network or social media platform (a “third party cookie”). Third-party cookies may be used to link your browsing behavior across multiple sites. Cookies are either stored for the duration of your visit (a “session cookie”) or they will remain on your device for a fixed period (usually several months, or longer) to remember you across multiple browsing sessions (a “persistent cookie”).
Other types of storage, such as local or “HTML” storage.
Many websites use local storage technologies that are similar to cookies but enable larger amounts of data to be stored. This means they can store information like your preferences and viewing history on your device rather than on their own systems.
Other tracking technologies, such as pixels.
Websites and email communications may also use embedded code to record how you interact with them (recognising your browser via the unique ID stored in their cookie or your device “AdID”). They are often used to send data about your browsing to a third party, such as a social media company or advertiser to measure engagement with their content or to personalise ads or marketing.
Tracking via Apps.
Companies are unable to use cookies within Mobile Apps. Instead they use unique identifiers associated with your device, such as the device Advertising ID (a random and resettable ID on your device), and other data such as your geo-location or your network location. This data is used in the same way as cookies, e.g. to analyze and improve services and to serve marketing and advertising to you (if the App is funded by advertising).