: It could simply be a generic archive of any data (videos, software, backups) that was too large to upload as one piece. In this case, "TDC" might be a specific project name or acronym unique to the uploader. How to Handle a .7z.001 File
A file ending in is the first part of a "split archive" created by the 7-Zip compression tool. This usually happens when a single large file is broken into smaller chunks to make it easier to share or download. TDC.7z.001
To see what is inside, you generally cannot open the .001 file alone. You must follow these steps: How to Extract .7z.001 files - Microsoft Q&A : It could simply be a generic archive