Frequent uses of modal windows include:
- Drawing attention to vital pieces of information. This use has been criticised as ineffective because users are bombarded with too many dialog boxes, and habituate to simply clicking "Close", "Cancel", or "OK" without reading or understanding the message.
- Blocking the application flow until information required to continue is entered, as for example a password in a login process. Another example are file dialogs to open and save files in an application.
*Source: Wikipedia