The following example teaches you how to determine if the Windows license you are running on computer your type is OEM, Retail, or Volume.
When you are going to buy a license of Windows, there are a number of different ways to do it. Depending on how you choose the licenses and other price, they also have different rights, constraints and names. The most common types of licenses are Retail (FPP (Full Packaged Product)), OEM (Original Equipment Manufacturer), and Volume Licensing.
For more information, see this one Microsoft link
Volume Licensing
They appeal to companies of all sizes who wish to obtain at least 5 software licenses by choosing one of the flexible pricing schemes, simplifying license management and enjoying additional product-related benefits (eg license transferability, downgrade rights, and the use of older versions etc.).
Pre-installed software (OEM / DSP)
The pre-installed software is available in DSP / OEM format and is designed to a) be pre-installed on new PCs and servers exclusively by computer/server manufacturers for the purpose of resale, or b) to accompany the computer or server in which it was originally installed by its manufacturer (System Builder or OEM Manufacturer)
Retail Packages (Retail / FPP)
Retail / FPP (Full Packaged Products) Retail Packages are available through retail outlets, both for home users and small businesses up to 10 PCs. They allow the installation and use of the software on 1 device. The package includes the key to activate the product and a storage or link to an online installation site.
But let's now look at how to understand if your Windows is turned on as Retail, OEM, or Volume.
1. Open a command prompt. To do this, press Win + R at the same time and in the executable window type "cmd" and press Enter
2. Type the following command at the command prompt, and then press Enter.
slmgr -dli
3. Μετά από ένα σύντομο space 5 δευτερολέπτων θα εμφανιστεί το παράθυρο διαλόγου του Windows Script Host where it will show what type of license you are running. (See images below):
