NoMachine, available for Windows, Linux and Mac lets you access the physical desktop remotely. So upon connecting your desktop is at your finger tips as if it were really in front of you rather than being on the other side of town, in the other room, or in another country. It allows one connection and is for individual use (home or office). If you are connecting to your desktop remotely, you will not be able to have a friend connect at the same time. If you are working on your local desktop and have NoMachine installed, a colleague or friend can connect to it to collaborate on a document and so on, or interact with you. They will need NoMachine installed on their computer, too.
Comparing NoMachine for Linux and NoMachine Workstation for Linux
There are three main differences between the two products.
1) Support for SSH is not available in the free version 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 supports virtual desktops.
3) NoMachine allows one connection to the remote host, Workstation allows 4 virtual desktops to run the on the host.
NoMachine requires that the X server is running. You can also use NoMachine on a headless Linux server (without the need of having the X server running), more instructions are available here:
Workstation is for Linux only and is a server-based computing product, part of the terminal server range. It will let you connect even if you don't have an X server running. When connecting to a Linux host which doesn't have an xserver running, you will be able to run "virtual desktop sessions".
Note for Linux users: If you want to connect to the physical display of a Workstation host, you will still need an X server running there.
As mentioned earlier, Workstation will allow you to run up to 4 virtual desktops (including custom sessions/single applications) on a Linux host. These virtual desktops are replicas of the operating system residing on the host e.g. Ubuntu. Each virtual desktop is separate from the physical OS, and each other. Any of the products from the Terminal Server range (e.g. Workstation or Terminal Server, https://www.nomachine.com/enterprise) allow to create virtual desktop sessions (with the exception of Enterprise Desktop).
The Workstation Pack and other Terminal Server (Linux) versions are intended for the enterprise market. The NX Free Edition 3.5.0 worked as a terminal server limited to 2 users. This functionality is no longer available in the free version 4.