It is urgent that your computers be backed up in an effective manner continuously. The good news is that it is easy and inexpensive to set up automatic back-up that requires no action on your part and has the characteristics we look for.
The back-ups should be incremental, that is, it should be possible to get back to any version. No back-up should overwrite any previous backup version. This is the best protection against ransom ware or other corruptions to your data.
The back-ups should be stored redundantly, so you still have them if any media fails and if something catastrophic such as a flood or fire or vandalism occurs. Luckily, this can be easily accomplished over the internet now so it is no longer necessary to move devices or media around.
There are two classes of devices we recommend for accomplishing the automatic back-up, and they can be used in combination with another instance of either class and/or a cloud back-up service.
It supports automatic incremental back-up of ALL your computers including redundant backup to a remote device or the cloud. It also enables remote access to computers you authorize, remoter access to shared data you authorize, hosting of certain apps, and more. The software is affordable and an appropriate server computer for it would be affordable as well.
It has similar features for back-up and sharing. There are also less expensive “personal” versions that might be adequate, especially as a remote, secondary store:
You can use one of these devices to back-up all the computers on premises, then you can have another stored somewhere else, such as your home, to back-up the back-up over the internet. You could also back-up the back-up to the cloud, such as with Microsoft Azure back-up services, but there would be a (reasonable) monthly fee for that.