How are drill bits made?

Depending on the quality - Poor quality cheap drills may be ground with a groove down each side and then heated up and twisted. the end is then sharpened.

Modern more upmarket drills are ground as they rotate to produce the spiral Flute. the end is then sharpened.

The drills are hardened and tempered to make them hard enough to drill metal etc.

Masonry drills have a tough carbide tip brazed onto the end to resist the abrasive effects of the brick / concrete dust as they drill