While the Enterprise mode functionality provides great compatibility for you on Internet Explorer 8 or Internet Explorer 7, the new document mode capabilities can help you stay up-to-date regardless of which versions of Internet Explorer are running in your environment. Therefore, we recommend that you start your testing process as follows:
If your enterprise primarily uses Internet Explorer 8 or Internet Explorer 7, start testing by using Enterprise mode.
If your enterprise primarily uses Internet Explorer 10 or Internet Explorer 9, start testing by using the various document modes.
Because you might have multiple versions of Internet Explorer deployed, you might have to use both Enterprise mode and document modes to effectively move to Internet Explorer 11.
Important
Enterprise mode takes precedence over document modes.