To access the content, you must:

Knowing the source can help me identify the likely data type.

Based on the filename structure, s0391.7z.005 is the fifth part of a multipart archive (file 5 of a set, likely from 001 to 005 or higher). These files are commonly used to split large data sets into smaller, manageable chunks [1].

Use a file archiver utility like to open the first part ( s0391.7z.001 ).

What is the (e.g., a specific software project, an online forum, a server backup)?

(001, 002, 003, 004, 005, etc.) into the same folder.

The software will automatically detect the other parts and extract the combined contents. To tell you what is inside, I would need to know: Where did you or receive this file from?