Original: It runs the browser inside the window space of another application e.g. in Microsoft Outlook , where the page was then made to look like the content one would expect in an email , leaving any passers-by with the impression the person was reading e-mail .
Simplified: The browser runs inside the window space of another program e.g. in Microsoft Outlook , where the page is made to look like the things one would expect in an email , making people think the person was reading e-mail .