A cookie can keep information in the user's browser until deleted. If a person has a login and password, this can be set as a cookie in their browser so they do not have to re-login to your website every time they visit. You can store almost anything in a browser cookie. The trouble is that a user can block cookies or delete them at any time. If, for example, your website's shopping cart utilized cookies, and a person had their browser set to block them, then they could not shop at your website.
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Cookie - Stored data in browser and will work on browser related and client side only.For example if you are trying to log in gmail account with username and password,After entered login successful if you close the current tab and after sometime opening same page the login page won't come it will open directly with login details.

Session - Stored data in server side for example same as cookie example after entered login details you will get notification as successful once you close the browser then open after some time it will ask again login details(more example shopping also)
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