Windows 10 comes in two versions: The Home and the Pro version. Within this version you can choose a Retail or OEM license.
The main difference between Windows 10 Home and Windows 10 Pro is that the Pro version may be used for business purposes.
With the Pro version, it is possible to have a secure boot, support file encryption and take over a PC by means of a remote desktop.
The difference between a Retail license and a OEM license is that an OEM licence may only be installed on new computers (new hardware).
This OEM licence may be installed once and is linked to the hardware.
Do you want to be able to transfer the licence when you buy a new computer? Then choose a Windows 10 Retail version.