Hunters-gathers were hunters. And never had a permeate house and were nomads for the search for food. And existed when there was really no main groups of people. And they hunted any thing that killed any thing that was edible.
Agricultural Revolution is the time when farmers domesticated animals so the animals can help them in their work and made it easy for their labor. People started to grow their crops so they can make more meals and not starve to deth.
When the nomads seteld down they wanted to trade with others so they develop jobs. One job they made was shipwrits. They started to make boats so they can travel faster down river. Boats were also helpful for fisher men that fished for fish in the river.