The industrial revolution concept first appears mainly in Arnold Toynbee and Engels. It is primarily used to describe the upheavals of the late eighteenth and nineteenth century. It is the affirmation of capitalism, the industrialization of Great-Britain, of Europe and the United States. But beyond this specific reality, today it's a more general concept, which is frequently used. Basically we can say that it means a major upheaval of the techniques and means of production, but with the specificity that these changes have an impact on almost all aspects of economic and social life. There are constantly technological changes in capitalism and some of them disrupt important specific aspects, but in reality we can only speak of a technological or industrial revolution when the upheavals caused concern most aspects of economic and social life in general. In this sense we can say that there have been so far two major technological revolutions in capitalism. The first began in the late eighteenth century with the steam engine, railways, etc. The second is electricity, which appeared straddling the nineteenth and twentieth centuries.