The interphalangeal joints of the hand are the hinge joints between the phalanges of the fingers that provide flexion towards the palm of the hand.
There are two sets in each finger (except in the thumb, which has only one joint):
"proximal interphalangeal joints" (PIJ or PIP), those between the first (also called proximal) and second (intermediate) phalanges
"distal interphalangeal joints" (DIJ or DIP), those between the second (intermediate) and third (distal) phalangesAnatomically, the proximal and distal interphalangeal joints are very similar. [Source: Wikipedia 
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