Cryptids are mainly plants, animals, and other Eukaryotas not recognised by the scientific community or thought to be extinct but some believe they are still alive today. Cryptids are, for the most part, creatures of myth and legend, or animals thought to have have taken new evolutionary paths and evolved from previously existing creatures into new variations.
Cryptozoology is the study of cryptids. It is the attempt to study mythical creatures in a scientific fashion. Cryptozoologists are those that study cryptids and cryptozoology. Cryptozoology is not recognised as a branch of science by mainstream scientists.
Just as cryptozoology, a branch of zoology, is the study of animals whose existence has not been proven, cryptography, a branch of botany, is the study of plants whose existence is not recognised by the scientific community.