...The free one is included on new devices sold by big brands, like laptops that come with Windows pre-installed. These manufacturers don't have to pay to include the codec.
Luckily, you can download the codec for free and install it on your own computer. That's what this file offers. After installing it, you can play videos and movies recorded with the HEVC (H.265) codec. Most 4K movies are recorded in this format, so with this application, you'll be able to play them using the native Windows application called Movies and TV.