Deforestation, by definition, is the clearing of a group of trees or a forest for a non-forest use, such as commercial purposes.
Or in other words, destroying an entire group of trees so people can build stuff on it.
But this is destroying the habitat of many animals, and in places around the world(not much in America if you're wondering) endangered species often live in those forests. Clearing forests destroys habitats and spikes up the risk of a species becoming endangered, if they still aren't.
There are ways you can help at home!
Always try to buy things that are recycled. Don't use real firewood in your fireplace. Try not to use a lot of paper(or go paperless!). And a lot of other things, too!
Or, you can always be direct:
Plant some trees!
Donate to a group/charity that plants trees or spreads forest conservation efforts!
We can all change...
and it starts with little things, and very little things.