What is industrialization? why was this concept important to marxism?

Industrialization is the development of industries in a country or region on a wide scale.

Other than that, he viewed industrialization as merely representing a further stage in the dehumanization of workers and as an essential stepping stone towards the revolutionary processes he was certain would come.  In his preface to the first volume of Das Kapital, he wrote that “[t]he country that is more developed industrially only shows, to the less developed, the image of its own future.”  If the feudal, agrarian society exploited the lower classes by enslaving them, the process of industrialization enabled the holders of capital to attain greater wealth through a more productive economic system, but always at the expense of the poor.  He had written his 1847 Poverty of Philosophy, in the chapter titled The Metaphysics of Political Economy, that “[i]n acquiring new productive forces men change their mode of production; and in changing their mode of production, in changing the way of earning their living, they change all their social relations.