Greetings.. Whats the difference between Original drivers and Windows drivers? Ok the short answer is none, but of course the full answer is a little more complex.
By definition a driver for a product that is designed to be installed on Windows IS a Windows driver. However there is a minor distinction between generally available Windows drivers and those provided by the manufacturer of the computing device you are obtaining the driver for.
Drivers provided by the manufacturer of a device are reffered to as original drivers, these are generally the drivers supplied by the manufacturer and shipped with the product when it was new. Lets choose an example. Lets say I bought a sony laptop 4 years ago. That laptop will come with a pre-installed Operating System that is already configured, it will already have drivers installed too, those drivers are referred to as the original drivers.
However Sony may have decided to use a device manufactured by NVidia and NVidia frequently release updated drivers that add extra features or performance benefits. I can go and obtain a driver for my NVidia device from NVidia's web site and install that in place of the driver supplied by Sony.
Sometimes computer manufacturers release a computer with a modified version of a device, in those cases it will only be possible to obtain and use drivers supplied by the computer's manufacturer. The drivers will usually warn you that this is the case when you attempt the install.