Because this is only "Part 1," you won't be able to open or play it on its own. You will need to download all the subsequent parts (Part 2, Part 3, etc.) into the same folder. Once you have the complete set, you can use a program like WinRAR or 7-Zip to extract the actual video file.

This is usually a shorthand code or abbreviation for the title of the content.

It looks like you’ve come across a piece of a larger archive, likely a high-definition video file split into multiple parts for easier sharing.

This is the first segment of a compressed archive.