There are two distinct types of sweat glands: eccrine glands, which produce the watery sweat that cools us down, and apocrine glands, which release a waxy sweat responsible for body odor. The latter becomes a breeding ground for bacteria, which metabolize it and create the unpleasant smell. Interestingly, sweat is salty because our bodies are essentially salty oceans, with the salt being an incidental component rather than a necessity for cooling.
