When you log in to your page4 website with your password to edit content, page4 saves a so-called session in the form of a cookie on your computer via your browser. This is purely for technical reasons, otherwise you would be automatically logged out after each action. As soon as you leave edit mode, all session data is automatically deleted.
Detailed information about cookies can be found on the Mozilla website. The statements made there apply to all browsers. Only the instructions how to remove cookies refers to Firefox and can not be transferred 1:1 to other browsers, as these of course have a different menu navigation.
Deleting cookies is as easy as deleting the browser cache. You can find information on the corresponding help page. With Mozilla Firefox and Google Chrome you have the option to delete cookies at the same place where you delete the cache. With Apple Safari, you have to do something different. Open the "Safari" menu, then select "Settings" and click on the "Privacy" tab. There you can click on the button "Remove all website data..." Delete cookies. The option "Details..." gives you an overview of all stored data and allows you to delete individual cookies or the complete list.
Important: If you delete all cookies, your browser no longer knows any pages you have visited and if you have indicated on pages such as Facebook, Twitter and Co. that your access data will be saved, then you must log in there again with your name and password once all cookies have been deleted. Otherwise, nothing can "break" just because you have deleted cookies.