Cookies track what you are doing through your web browser. If used legitimately, this information about your browsing activity is gathered with your permission and knowledge to better target ads at you or provide a better browsing experience by remembering where you were, the convenience of remembering a login for example. Cookies are also spyware and so can be used for malicious purposes. It’s a good idea to log out of all browsers before doing sensitive transactions such as internet banking. It is perhaps also safer not to allow your browser to remember your passwords, particularly for critical sites or those that hold sensitive information or information of high consequence, to browse in incognito or in-private mode and regularly delete browsing history.