Yes, if you login and enter username and password and tick the box on the website to remember you or the website supports this feature then a special sessionID cookie is created and stored on your computer. As long as you have this sessionID cookie and it is valid (session hasn't expired) then this cookie can be used to login automatically instead of entering username and password. If you logout manually then you invalidate this sessionID cookie that remembers you. ---- Detail like websites remembering you and log you in automatically is stored in a cookie. You can use these steps to make a website recognize and remember you. *create a cookie allow exception with the proper protocol (https:// or http://) to make a website remember you You can check that you aren't clearing important cookies. *using "Delete cookies and site data when Firefox is closed" keeps cookies with an allow exception *using "Clear history when Firefox closes" to clear cookies clears all cookies including cookies with an allow exception you may want to keep *clearing "Site Preferences" clears exceptions for cookies, images, pop-up windows, and software installation and exceptions for passwords and other website specific data *Settings -> Privacy & Security<br>Cookies and Site Data: "Manage Exceptions/Permissions"