Because Android detects duplicate applications, it is not possible to install the same application more than once without having previously deleted the previous installation. This in practice, among other things, means that it is not possible to have two user accounts in apps such as WhatsApp or Facebook, which do not have multi-account support. However, to avoid this we can resort to a parallel space app, such as VPhoneGaga.
A virtual machine to duplicate applications
This application works as a virtual machine and thanks to it you can install apps that you already have installed on your device because it works as a watertight space, apart from the main operating system. This allows us to install apps such as WhatsApp or Facebook and use more than one account simultaneously without having to enter our user credentials every time we want to switch accounts.
But the usefulness of a virtual machine is not limited only to duplicate applications, but can also serve to have a private space where you can have hidden files, a separate workspace or a place to test applications that may be potentially dangerous to the device. And all of this, as we say, without any impact on the operating system of our Android.