NoMachine Free Edition, free for non-commercial use and available for Windows, Mac, Linux and ARM, provides remote access to the physical desktop. When installed on the computer you want to access, it allows one incoming connection. It can also be installed on the device you are connecting from to initiate unlimited remote access connections to other NoMachine-enabled hosts. If two or more users need to connect to the same physical desktop at the same time, Enterprise Desktop is a better fit.
Check out the comparison here: https://www.nomachine.com/remote-access-for-everyone.

NoMachine Workstation, from the NoMachine Terminal Server family, is a product aimed at Linux users. Any of the products in the Terminal Server suite lets you run multiple Linux desktops concurrently on the Linux host where it is installed. These are called "NoMachine virtual desktops" or "virtual desktop sessions". It is also possible to access the physical display of the Linux system, but the principle functionality of the Terminal Server products is their capability of running multiple individual Linux desktops on the same host. Multiple users, connecting at the same time, can have their own personal 'virtual' Linux desktop according to how the Administrator has configured it. Each virtual desktop is separate from the physical OS, and each other.

Comparing NoMachine for Linux and NoMachine Workstation for Linux

There are four main differences between the two products.

1) Support for SSH is not available in the free edition of NoMachine. SSH support is available in the Workstation.

2) The virtual desktop functionality is not available in the free NoMachine for Linux package. Workstation is designed for virtual desktops.

3) NoMachine Free Edition allows one connection to the remote host, Workstation allows 4 virtual desktops to run the on the host and an unlimited number of connectsion can access those 4 virtual desktops.

4) NoMachine Free Edition doesn't support connections via browser. Connections to the remote computer via browser are available in the Workstation (and all other products in the Enterprise products)