About an year ago Microsoft announced the plan to retire Internet Explorer. The new browser, Microsoft Edge, is now the default browser in Windows 10.
Edge has many security improvements. It does not support legacy technologies such as ActiveX and Browser Helper Objects. The new layout engine, EdgeHTML, is a fork of Trident (the layout engine of Internet Explorer) that has removed all legacy code of older versions of Internet Explorer. EdgeHTML is meant to be fully compatible with the WebKit (the layout engine used by Google Chrome).