A gland is a unit of tissue structure and its function involved in the manufacture and discharge of secretion. It may be classified in many ways. In using a nomenclature, combination of various classifications is used. They can be categorized according to number of cells involved, size, morphology, branching of the duct, presence of ducts, type of secretion, and damage of secretory cells at discharge. Salivary glands are multicellular, merocrine and exocrine glands. They may be classified according to size, location or type of secretion. There are three pairs of major glands—parotid, submandibular and sublingual. A salivary gland consists of parenchymatous secretory cells and stromal connective tissue.