In the Paleolithic age, we hunted for animals and gathered plants. We did not have a very dependable food supply so we had to migrate a lot because the food would go scarce from so many people in one spot for a long time
The first important change is that we learned to domesticate animals. We raised them to help us with our needs such as work and food.
The second most important change is that we began to plant our own crops. We now have a more stable food supply.
It is the business of farming such as growing plants and raising animals. It was important because for the first time they had control over their food supply.