Video_2021-.7z

if you want the absolute smallest file size for long-term storage and plan to extract the entire archive at once.

The in a .7z archive (like your video_2021-.7z ) is a compression method that treats multiple files as a single, continuous data block rather than individual items. video_2021-.7z

: To extract just one file from a solid archive, 7-Zip may need to decompress all preceding data in that solid block, making single-file retrieval much slower than in a non-solid .zip . if you want the absolute smallest file size

: All uncompressed files are concatenated and processed together. This allows the algorithm to find similarities across different files. : All uncompressed files are concatenated and processed

While it can significantly improve compression ratios, it has specific trade-offs for video files: How it Works

if you need quick access to individual videos without waiting for the whole set to process. Does 7z compress better than zip? - Microsoft Community Hub