Heel vs sole.
Here God is talking to the serpent saying that God will put an enemy between him and man. Him being Jesus Christ. This is the first mention of the coming Savior of mankind.
In those times, in the lands and times of the bible, a bruise to the head was almost always certain to be a deadly wound, definitely causing death. Whereas a bruise to the heel only meant a temporary and healing wound that would only incapacitate for a short time. A bruise only, not deadly.
Jesus Christ did die, but he arose the third day. Why three days and three nights. Well in those times there had been instances where folks were buried, but they later revived. They were not diagnosed properly! Kek! So, they set a time limit that they'd all be satisfied that the person was firmly without question absolutely DEAD, and that was three days. So, Jesus Christ was definitely dead, but he arose, then in from of many witnesses he rose into the heavenlies, he Ascended! The first man to do that in history, the first, not the only!!
God Wins!!