The gums are also known as the gingivae.
("Gums" is the colloquial term used in everyday English whereas "gingivae" is the anatomical term used in medical textbooks, research papers and other documents.)
The gums are the ridge of oral mucosa located at and surrounding the base of each tooth and so forming two continuous "gums", one attached to the upper-jaw and the other attached to the lower-jaw (upper jaw bones = maxillae; lower jaw bone = mandible).
The gums are just one of the structures in the human oral cavity. See also the links to pages about other parts of the mouth.
The topics of digestion and teeth are included in some school e.g. GCSE and/or A-Level courses in subjects such as biology and human biology and in other courses that include human anatomy & physiology, diet, nutrition, and other health sciences.