The role of browser plug-ins
A browser plug-in expands a web browser's functionality by installing specific toolbars, adding buttons, links or other useful functions (like pop-up blocking). Legitimate browser plug-ins are not only harmless, but also very handy. Popular plug-ins include the Google Toolbar, MSN Search Toolbar, Macromedia Flash or Adobe Acrobat Reader. However, not all plug-ins are created equal.