Hunter-gatherer's lived in caves. They hunted fish, rabbits and other animals. They lived by the water to have water to drink and fish to eat. They used weapons like bows and spears. They are known as "nomads" because the moved around a lot to follow their prey. The only way they could stay alive was to find animals for food and water to drink.
Farmers used animals to help till the soil so they can grow crops like corn, wheat, oats & barley. They used cows for milk and meat. They got water from wells that they would dig and pump. They used this water to irrigate their crops and to grow fruit trees. The farmer's then take the excess food to sell to people to get money. Man was no longer a nomad.
Life improved by having a stable food supply. They no longer feared that they would be killed trying to get food or water. Farming became an industry that led to communities, which created jobs and growth in all areas of life. Railroads, wood mills, general stores, cotton & wool fabric, and schools. All of this happened because of the domestication of animals.