Because you are pulling directly from a server directory, download speeds are often much faster than those found on "free" streaming sites. How to Use Google Dorks for Better Results
If you are a site owner, seeing your files in these results means your server is "leaking" information. You should disable directory browsing in your .htaccess file to keep your data private. The Bottom Line Index Of Mp4 %21%21BETTER%21%21
This specifies the file format. MP4 is the universal standard for high-quality video with relatively small file sizes. Because you are pulling directly from a server