Two basic types of drilling bits exist, those with 1 of more rotating cones and those with fixed cutting structures.
Most drill bits with rotating cones comprise three (3) journal bearing cones which are called tri-cone bits which have either mill tooth shaped teeth or inserts embedded in their cone shapes.
Modern drilling bit advances have resulted in Polycrystalline Diamond Compact (PDC) bits.
PDC CUTTER BIT
FIXED CUTTER BITS