The .7z.001 extension indicates that a large file was compressed using 7-Zip and then sliced into smaller chunks. : This is likely the specific project or file name.
: This identifies this specific file as Part 1 of a multi-part set. Step 1: Gather All the Parts S1 396.7z.001
: This is the compression format (similar to .zip or .rar). S1 396.7z.001