Town lifestyle (I assume you mean by this: a settled lifestyle , so that it contrasts with the nomadic lifestyle) comes with more security: you can store your food reserves and plan for the future. 
nomadic lifestyle gives you more flexibility but less security: you can travel elsewhere if your fodosource is runnign low... but usually this is not as good of a food source as a settled lifestyle. One other possible advantage could be being merchants: nomads can benefit from a trade. 
        
             
        
        
        
Here you go
Explanation:
Societies that rely primarily or exclusively on hunting wild animals, fishing, and gathering wild fruits, berries, nuts, and vegetables to support their diet. Until humans began to domesticate plants and animals about ten thousand years ago, all human societies were hunter-gatherers.
 
        
             
        
        
        
Healthy ecosystems clean our water, purify our air, maintain our soil, regulate the climate, recycle nutrients and provide us with food. They provide raw materials and resources for medicines and other purposes