system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why does armpit sweat have a stronger smell than other sweat?
gpt
You have two different types of sweat glands. Your basic salty, watery sweat is produced by eccrine glands that area all over your body, these mostly just help keep you cool. They secrete directly onto the surface of your skin.

Then you've got your apocrine sweat glands. These become active during puberty in places like your ears, armpits and groin. These glands are fancy sweat glands, they dump their secretions through a hair follicle and travel to the skin that way. It's thicker too, more like an oil than water. The sweat from these glands also contains more stuff than your basic sweat. This extra stuff attracts bacteria on your skin that breaks everything down into acids. That's what smells. 

Apocrine glands respond to hormones (adrenaline) instead of temperature, which is why you might sweat more when you are nervous, in pain, sexually aroused etc.