One of the major characteristics of pre-industrial times was the lack of machinery to automate or speed up work of various kinds. Because of the limits this placed on all types of production (agricultural, etc.) a huge portion of the population existed as subsistence farmers working to support their families from what they could grow or raise on the land available to them. Anything complex was built by craftsmen who could produce one at a time. As an example, books were rare given that the only way to reproduce them was for experts to copy them by hand. A large portion of the population was illiterate, disease was rampant and massive levels of inequality existed.
As machinery developed and increased the means of production by magnifying the labor of individuals, the standard of living for most individuals increased. The development of textile making, water power, steam power and iron production allowed for an increasing middle class and eventually the mass production of consumer items that had been rare and incredibly expensive that transformed the daily lives of massive portions of the population. Cities began to grow rapidly as factories sprang up and were hungry for labor.