Often developers confusing regarding the following IE modes. Simply I explained below what does, each one.
It is an identifier of browser version which is used in code.
This is only renedering the page using IE engine.
This is changing the browser mode and document mode to lower version i.e IE7. This is mostly creating a problem in production environment in IE.
> Developer can force document mode to Edge. Means, IE automatically changed to highest version of browser.
> It is very useful for fixing the compatability mode issue.
> Anyway, developer can not force browser mode. So still your apps gets problem if you ae checking with IE versions in code level.
<meta http-equiv=”X-UA-Compatible” content=”IE=edge”>
> If you are not mention doctype, then your browser gets old browser engine and some of the functionality will not works fine in your app.
> Use standart doctype <!DOCTYPE html>
> Use doctype <!DOCTYPE html>
> Add X-UA-Compatible to edge
> Both mode (Browser mode & Document mode) should same in your testing scenarios if edge mode not enabled.