If you are building a ‘modern’ web application for Internet Explorer, I would recommend to enable the following header inside your web.config:
Using this header will enable ‘Edge mode’ inside IE. It represents the highest support for modern standards available to the browser. In other words, it tells Internet Explorer to use the highest mode available to that version of IE; e.g. Internet Explorer 8 can support up to IE8 modes, IE9 can support IE9 modes and so on. Edge mode was introduced in Internet Explorer 8 and has been available in each subsequent release. Note that the features supported by edge mode are limited to those supported by the specific version of the browser rendering the content.
Remark: Starting with IE11, Edge mode is the default mode. Other document modes are deprecated and should no longer be used, except on a temporary basis. Make sure to update sites that rely on legacy features and document modes to reflect modern standards.