In common with other websites, log files are stored on the web server saving details such as the visitor's IP address, browser type, referring page and time of visit.
The information is used to enhance the visitor's experience when using the website to display personalised content and possibly advertising.
Cookies are small digital signature files that are stored by your web browser that allow your preferences to be recorded when visiting the website. Also they may be used to track your return visits to the website.
Google's use of the DART cookie enables it to serve ads to visitors based on their visit to sites they visit on the Internet.