Windows 10 is available in two versions: The Home and the Pro version. Within this version you can opt for a Retail or OEM license.
Windows 10 Home and Windows 10 Pro is that the Pro version can be used commercially. With the Pro version it is possible to boot up securely, it supports file encryption and a PC can be controlled by the means of remote desktop.
The difference between a Retail and an OEM license is that an OEM license can only be installed on new computers (new hardware).
This OEM license may be used for installation once and afterward it is bound to the hardware of that computer.
Do you want to be able to transfer the license when you buy a new computer? Then choose for a Windows 10 Retail version.