As kids go through puberty, there are special sweat glands that start working for the first time. These glands are found only under their arms and around their genitals. The sweat from them contains proteins and carbohydrates that mix with the bacteria on their skin to cause an awful smell. Showering with warm water and cleaning with a mild soap washes away the bacteria and helps control body odor. Wearing clean clothes, socks, and underwear every day also helps.
If you (and others around you) don’t like the way your armpits smell, you should try using a deodorant or antiperspirant. The difference between deodorants and antiperspirants is that deodorants cover up the smell while antiperspirants stop or dry up the sweat. They are two different ways to solve the same problem. Give both a try to see which works best for you. Your friends and family will love you for it!