Glands are specialized organs in the body that produce and release substances such as hormones, enzymes, or other fluids. They play a crucial role in regulating various bodily functions, including metabolism, growth, and mood. Glands can be classified into two main types: endocrine glands, which release hormones directly into the bloodstream, and exocrine glands, which secrete substances through ducts to specific locations. Examples of glands include the thyroid gland, which regulates metabolism, and the salivary glands, which produce saliva to aid in digestion. Each gland has a specific function and works in harmony with other systems in the body to maintain overall health.