The advent of farming is one of the most impactful things that can happen to any population. It can completely transform the way in which the people live. Let us look at some of the most important impacts.
First, farming allows for greater population sizes and densities. Farming can produce a greater amount of food per unit of land than hunting and gathering can. This means that larger populations can be sustained.
Second, farming allows for sedentary living. Hunter-gatherers generally have to move from place to place in search of food. It is generally not possible for one area to sustain the population full-time. Farming can sustain large populations. This meant that farming brought about large, permanent settlements.
Finally, farming leads to complex civilizations. Hunter-gatherers tend to live in small groups who are all related to one another in some way. They do not have much in the way of hierarchy. When permanent settlements arise, large numbers of unrelated people live together full-time. Hierarchies tend to arise. This leads eventually to situations such as that in Central America with political and religious elites having a great deal of power, wealth, and prestige and ruling over masses of people who lacked those things.
In these ways, farming completely changes the lives of people when it arises in a given region.