There are different types of communications
AMR Shared cloud
It's cloud based database with some shared templates with some other clients. It's convenient for starters but it doesn't allow customization of reports and logos.
Data can be accessed from the internet.
AMR Private cloud
It's cloud based database only for your company. It allows customization. You have the access keys of the cloud and can change them when you like.
Data can be accessed from the internet. Ideal to use QR code tickets.
On premises - In your own server
Server it's installed in your own local server. It allows customization. It requires maintenance of the hardware and Windows software.
Data can be accessed only from local network. To allow external access you'll need to open a port. To use allow clients use QR code ticket, you'll need to open a port in your router.