Standard License (node locked) - The standard license option applies to a single, standard C4D license. This is for regular C4D installs, without a license server.
Standard Floating License - If you are not running over a License server, you can use this license to run a single DEM Earth license, on different workstations, using one account. You can have multiple machine numbers in your account, as long as they are your machines. this allows you to run DEM earth at work, and at home, etc.
Floating License over Network Server - if you want to run a single DEM Earth seat over a network license, you need to select this option. You can then install, and use the plugin, on a single workstation, within your network. (e.g. you have a 10 seat server license. (20601012345-xxxx-xxxx) but you only want to run one workstations with DEM Earth.)