Details of all the Web sites and Web pages that you visit while browsing the Internet are saved in your browser’s History. During your browsing session, a number of files may be stored in the temporary memory (cache memory) of your computer, recording information about your online activities.
These temporary Internet files may contain personal information, such as your username and password, which could be accessed by hackers. To prevent this from happening you should regularly delete the contents in the browser history and cache memory.
If you visit a Web site that you have visited before, you may notice that it displays your name. This is done by using cookies, small files stored on your computer by Web sites to identify and track your preferences.
Site owners claim that cookies can help them provide a personalised browsing experience, but they can also be a threat to your privacy because they contain personal information, such as credit card details that you have entered while shopping online. It is a good idea to delete cookies regularly to avoid misuse of your personal information.
Programs are available to allow you to delete all traces of online activity, including cookies, from your computer. Ccleaner is a popular free product for doing this. You can see a video review here.