An exit is the way out of somewhere, or the way to leave. An exit might be a place or something you do, for example "he exited the room".
The opposite of an exit is an entrance.
A factory is a large industrial building where people or machines make things on a very large scale. Things like cars, toys and most common household goods are made in factories.
A farm is a large area owned by a farmer. On a farm, animals and crops are grown on a big scale. A farmer may have hundreds of acres of wheat and thousands of sheep or cows. Farms are where food is grown for all the people who live in cities all over the world.
Farms can have many crops or just one or two. A farmer might have an apple farm, or a chicken farm instead of having lots of different things.