An infarct is a dead area of tissue. Embolization is where a blood vessel is blocked and so the tissue that is fed oxygen, sugar, and other nutrients like amino acids for building proteins by that blood vessel does not get fed and dies. A coil is likely a curled up wire that is released from a catheter and which has a memory and assumes a coil shape blocking a blood vessel when released from a catheter. This may block a blood vessel. Embolization is a treatment which can be used to kill areas of cancer as if you cut off their blood supply by blocking the blood vessel after inserting a catheter into it, you may kill the tumor or part of the tumor (cancer).