The salivary glands in mammals are exocrine glands that produce saliva through a system of ducts. Humans have three paired major salivary glands (parotid, submandibular, and sublingual) as well as hundreds of minor salivary glands. Salivary glands can be classified as serous, mucous or seromucous (mixed).
There are 3 major salivary glands:

1. Parotid Gland: Parotid glands are the largest salivary gland. Each gland is approximately 6cm long. They are located within each of our cheeks. In our oral cavity they are responsible for the secretion of about 20% of saliva.
2. Sublingual gland: It is the smallest of the major salivary glands. They are located under the tongue. Approximately 5% of the saliva comes from these glands.
3. Submandibular gland: These glands are located beneath the lower jaw, outside the oral cavity. This is the movable part of our jaw. It is the second largest salivary gland and produces approx. 65-70% of saliva.