Answer: A factory is any place where goods are manufactured. The name itself comes from he Latin for "oil press" a machine for extracting oil from olives.
Early factories could have been a group of neolithic hunters getting together to do up a supply of flint arrowheads. As time passed these efforts grew and now factories are generally large buildings or groups of buildings dedicated to making a specific product.
To a visitor it may look confusing machines and people all doing "things". However each process has its purpose and adds to the completion of the product. Factories are a logical and interacting collection of workstations.
Physically a factory can be large, it may have smells from the hot metal or plastic being used. It is generally noisier than an office and it is generally quite busy with many people working at once.
Answer: Factories are a waste of space, they are full of machinery like looms and weavers. they kill the environment.
They will clog up the air and no-one will care because they don't think that our planet will die, but it will!