Historical materialism is the science of history explaining how the driving force of history is material conditions, relations among producers, and class conflict.
Historical materialism acknowledges the culmination of history in the present and its dialectical development into the future. This is called "world-history".
What most people know as "world history" is an undialectical and often revisionist retelling of history, utilizing Great Man Theory, incorporating historical nihilism, and other distortions and falsifications. The truth of world-history lay in the observation of history in its totality: the history of humanity; of human culture, of the sciences, of phenomenology, of class society and relations, of social (political, social) movements, of states, of our environment and how we interact with it-- the history of humanity, world-history, incorporates all of the elements of human history on Earth in their development and interconnection. More specifically, the proletariat bears the weight of all human history and its culmination in the conditions of this class's birth and development, and seeks to move forth the development of humanity out of global capitalist exploitation and alienation-- to return to a "lost" human spirit.
Thus, the history of human existence must be regarded as an objective (material) being, and should be recorded in such a manner as to counter the falsification of history-- whether such falsification be by means of lies, suppression or outright destruction of historical records, or other forms of historically nihilist information warfare.