There are several different terms with similar but different meanings;
a process of preserving cells by cooling them to extremely low temperatures. This process aims to avoid damaging the cells, so that they can be revived at some time in the future. This is successfully used for blood, bone marrow and other types of human tissue.
a specific type of cryopreservation, cryonics is the attempt to preserve a person’s entire body after death. Cryonics aims to preserve the body until a time in the future when the person could be resuscitated and brought back to full health.
for most people, ‘cryogenics’, ‘cryogenic freezing’ or 'cryogenically frozen' are common terms that first come to mind when we think about preserving bodies or tissue by freezing. However, cryogenics is actually a term used in physics, meaning the study of how materials behave at very low temperatures. Cryogenics does not necessarily have anything to do with biology or preserving tissue, although sometimes the term is used interchangeably with cryopreservation, such as in medicine.