SK is a document file that stores browsing history for Safari web browser. SK files contain full information about visited websites and dates of visits to given websites. Browsing history can be erased by removing SK file or by using appropriate option available in browser’s menu.

SK files store data in binary format and cannot be edited or viewed using other application than Safari for security purposes. Depending on browser’s privacy setting, a password may be required in order to access Safari’s browsing historys.