Before computers, fingerprints were stored on cards and categorized by the patterns made by the ridges. To make a match, a person had to look at each card of that type and manually verify the match. It was a slow and tedious process. Today, prints are converted into mathematical templates. In a template, specific features of the fingerprint called minutiae points are mapped.
The major minutia features are ridge endings, bifurcations and short ridges. The minutia points are identified and a vector is created from the point to the fingerprint core. A fingerprint template is a mathematical representation of the minutiae points and their relationship to each other. Templates are much smaller than images. A fingerprint template can be as small as 600 bytes and a fingerprint image is around 500,000 bytes. The smaller size means they are faster to match and less expensive to store. Even though the computer finds the likely matches in the database, a human being always verifies the match using the images.