These are not different versions, these are different apps. An app can have any name regardless of other apps' names. I have two "Camera" in my phone. One was pre-installed and the second is Google Camera that also has name "Camera".

These are not different versions, these are different apps. An app can have any name regardless of other apps' names. It is possible to have hundreds of apps with the same name on one phone because the name you see as a user has nothing to do with the name which sees Android (for example the system name for Shazam is com.shazam.android).

I have two "Camera" in my phone. One was pre-installed and the second is Google Camera whose visible name is also "Camera".