This has been a feature for as long as I can remember.
Keep in mind that an alias is the same site with different url. If you want a different content you need to setup a new site (which can be within the same application). Also if it's a new site it might need a license for it.
The link to the Documentation Brian shared you can see a version drop down at the top of the screen. If mapped you will switch to the same info in another version.