The file "Pokemon Legends Arceus (nsw2u.xyz).7z.001" is the first part of a split 7-Zip archive, requiring all associated parts (.002, .003, etc.) to be in the same folder for extraction using tools like 7-Zip or WinRAR. Users must download all segments to properly reconstruct the Nintendo Switch game file, while also taking precautions against malware and ensuring they have the necessary, uncorrupted files for gameplay.