cookies and website data
Websites often store cookies and other data on your Mac. This data may include information that you have provided, such as your name, email address and your preferences. It helps websites identify you when you return so the site can provide services for you and show information that might be of interest to you.
Safari uses machine learning to identify advertisers and others who track your online behaviour and removes the cross‑site tracking cookies and website data they leave behind. You can turn off Intelligent Tracking Prevention so that Safari always accepts cookies and website data or you can select to keep Intelligent Tracking Prevention on.
Choose Safari > Preferences, click Privacy, then select “Prevent cross-site tracking”.