What fingerprint classification involves friction ridges entering and exiting the same side of the finger pad?

The classification of fingerprints that involves friction ridges entering and exiting the same side of the finger pad is known as a loop. In this type of fingerprint, the ridges begin on one side of the finger, curve around, and exit on the same side. Loops are one of the most common fingerprint patterns and can be further categorized into radial loops, which flow towards the thumb, and ulnar loops, which flow towards the little finger.

Understanding loops is crucial in fingerprint analysis as they provide important information for identification. The presence of a loop pattern signifies that the friction ridges perform a circular motion rather than forming a complete whorl or a straight arch. This unique characteristic makes loop patterns distinguishable and helps forensic experts in their work.