According to Guns, Germs, and Steel, under what kinds of conditions does technology develop? How and why did technology development differ from one place to another?

For Jared Diamond in Guns, Germs, and Steel, there are several necessary preconditions for the development of technology. The single most important of these in an increase in food production by means of domestication of plants and animals. In settled communities that have undergone the neolithic transition one finds a virtuous cycle of food production increasing population and the population then increasing food production. 
Because agriculture is significantly more efficient than hunter and gathering, it creates a food surplus that allows people to engage in activities not directly related to food production such as developing various forms of technology. 
The final precondition for technological development is relatively easy access to raw materials. For example, easily accessible metal deposits allow for the development of metallurgy. Being located in areas where there are efficient trade routes allows cross-fertilization of ideas, something that also fosters technological development.