As Google Play Store allows app developers to publish different APKs of the application, these APKs are targeted for different device specifications, such as different CPU architectures and Android versions.
Although these APKs have independent versions, they share the same app listing on Google Play.
Some apps may show different app versions based on device specifications, which is listed as "Varies with device".
For example, if you release Google Map to a mobile device and a tablet, Google Play will distribute the most compatible app version based on the device configurations, which means the app version of the mobile device may not be the same as the tablet.
For more details of using Managed Google Play, please refer to this article.