When a file is too large, it is split into .part1.rar , .part2.rar , MSTER18-MW.part3.rar , etc.
These files are often password-protected. Ensure you have the password from the source where the file was obtained.
Potentially a version number, project name, or identifier (e.g., Master 2018).
A file (Roshal Archive) is a proprietary archive file format that supports data compression, error recovery, and file spanning [1].