When fingerprints are processed for the computer this is called file conversion. The database contains two types of records when first established. The first set of fingerprints are the thousands of cards that have been in file for years. These arrests can go back decades. The second set of fingerprints are the new arrests that are made every day.
File conversion involves getting all the fingerprints eventually in a computer database.
Once all the fingerprints are entered into the database two very important functions can be performed. The first AFIS function is maintaining a person's arrest record. As an example, let's say a person is arrested and refuses to give his name, or even more likely, gives an alias name. Not a real problem if you understand the fingerprint system and how it is implemented. So John Doe is fingerprinted and the AFIS encodes his prints and searches against all the fingerprints in file.