Cotton boll is the name of the rounded seed pod of the cotton plant. The fibres harvested for cotton develop within the boll and are part of it. See the Web Link to the left for more information.
A cotton boll is the locks of fluff that grows cotton plant on it. then it is picked and used to make different pieces of clothes such as jeans or t-shirts...etc.
Do you mean what are cotton bolls? Cotton boll is the name of the rounded seed pod of the cotton plant. The fibres harvested for cotton develop within the boll and are part of it.