Large datasets or software backups are often split into smaller pieces like this to:

: You only need to right-click and extract the file ending in .001 using a tool like 7-Zip . The software will automatically pull data from the .002 piece to complete the extraction.

To access the content within this file, you must treat it as part of a set:

Do you have the part of this archive, or are you trying to repair a set with a missing piece? 7z.001 7z.002 7z.003 help please - SourceForge

: If you just want to merge them back into a single large archive, you can use the "Combine files" feature within the 7-Zip File Manager. Why files are split this way