The intention of the directive was to combat "tracking cookies" and other similar techniques used by advertising networks to analyse your online behaviour and offer targeted ads to you. Cookies are small text files, stored on your computer by a website, that contain short pieces of information. These can range from the contents of your shopping basket to a unique (ish) identifier used by large ad networks to track your browsing history. Whilst the files themselves are harmless, many privacy groups object to the non-consensual tracking of an internet user's browsing habits. The "unique" identifiers used do not contain any real personal information and cannot track you across different computers or even different browsers on the same machine, however they allow ad networks to build up a profile on the person using that computer based on their browsing habits. By analysing what sites you visit that contain their adverts, they can make an educated guess of your age and gender and get an insight into what you read about, therefore allowing them to show you adverts that have more relevance to you, in turn allowing them to charge more for the placement of those adverts.