Large files (like high-definition videos, software installers, or massive datasets) are often split into smaller "volumes" to make them easier to upload, email, or store on limited media like USB sticks.
The .001 indicates it is the very first part of the sequence. 1 (7)-7 & 1 (8)-8.7z.001
To get the actual content out of these parts, you need a specialized file archiver. 1. Download the Right Tool Large files (like high-definition videos