After finishing your work, you may want to clear all cookies created by the browser so that no other person can access your account in those websites. For example, you used a public or friend’s computer to sign into some websites. Many times people clear these cookies stored by the web browser for privacy and security issues.
These cookies are created to stay you logged in to all websites so that you don’t need to enter your account credentials (username and password) every time you visit those websites.
When you sign in to a website (such as email website, social networking website, online forums, etc) using your web browser, one or more cookies are automatically created by your web browser to store your login information.