As you browse websites, cookies are stored in your browser. But not all cookies are the same.
There are two types of cookies:
Session cookies are temporary cookie files, which are erased when you close your browser. When you restart your browser and go back to the site that created the cookie, the website will not recognize you. You will have to log back in (if login is required) or select your preferences/themes again if the site uses these features. A new session cookie will be generated, which will store your browsing information and will be active until you leave the site and close your browser.
Learn more about session cookies.
Persistent cookies are files stay in one of your browser's subfolders until you delete them manually or your browser deletes them based on the duration period contained within the persistent cookie's file.
Learn more about persistent cookies.