I lost a 8gb micro SD card somewhere around my home, which has the original Zip files of Homebrew game roms on it. The extracted files are on my 32gb micro SD card in my New 3DS.
Do I have to keep the extracted folder of Roms such as GBA or NDS (as extracting feels like copying whatever I want in the folder) or is the extracted file also original?
They are the same.
You can recreate the compressed files from the unzipped files and they will work exactly the same.
Long answer.
Compressed formats do not alter the original information. What they do is reduce the size by looking for repeating patterns. But never altering the original information.
You can compress, decompress, recompress and uncompress again. And the information in the files will always be exactly the same.
What exactly do you mean with original? There is no such thing as original in the context you provided. Downloaded digital files are always copies.
If you fear data degradation, archives are lossless compression, as hechelion explained. Image compresssion as with jpgeg files is lossy, there is a difference between stored and displayed and when your recompress.
All that being said, there can be some technical differences. Meta data in the archive and even the file name of the archive. And of course if you keep the files somehwere, where they might be modified. For instance if the rom comes with a save game or whatever. It is bad practicse to modify installed files, but we are talking about homebrew roms here and I have no idea what is done there.
If the archive was merely a way of transporting the files and the files were not modified, you can just rezip them to have a new archive for safekeeping somehwere not so tiny as a thumbnail.
