Microsoft Edge is the new browser coming bundled with Windows 10, being very similar to internet explorer but with new and improved features. Microsoft Edge now uses an extension system, much like rival internet browsers Firefox and Chrome. It is now streamlined to be much faster than internet explorer.
Because this new browser has been completely rebuilt in a new engine, this browser no longer supports plug-ins such as active x. Internet Explorer is not being gotten rid of entirely. It will still exist as there will be a need for compatibility with older technology.