What does cookie mean?
A file of minute proportions that is saved on a mobile device or a computer that stores important information relating to the interaction of the user with the site. By accessing the cookies on a computer you can track what sites have been visited, and the exact pages within that site.
When sharing a computer, or using a computer in a public building such as a library it is vital that you clear the cache of cookies before logging out for security reasons. When you fail to clear your cookies, people can access your personal details, and the professional hacker can steal your identity in just seconds.