The notion of power is one which has existed throughout the history of class society. The features of power and the motion of its development has meant exhausting study in the field of philosophy and social theory; being the subject of immense investigation early in the tradition of metaphysics and later up until the current epoch in the science of dialectical materialism and contemporary post-modern/post-structuralist thought. The question of power, how it functions, and its various relationships is still incredibly pertinent and increasingly muddled; without a correct understanding of theory we cannot hope to develop correct practice and therefore achieve real revolutionary aims.
The expansive historicity of power in thought requires a fair amount of philosophical understanding. For the sake of concise analysis and criticism we will discuss only the more contemporary thought on power and leave most of its previous progress for the investigation of the reader.
While various interpretations of power exist with divergence among similar schools of thought we will crudely outline two positions of contradiction for the sake of easy acquisition.
The first is a more academically accepted understanding which first found prevalence in French academia but has now also made a home in the United States. Post-modern thought and in particular the post-modern conception of power reflects the aforementioned rejection of ‘totalizing’ systems of thought. Meaning that the post-modern conception of power rejects what has been considered the totality of thought regarding power and its reproduction within class society specifically by more traditional schools of Marxism. Some of the most instrumental contributions to this understanding of power, at least in the early stages of what would later be considered post-modern thought, come from an Althusserian student Michel Foucault. Foucault’s work influenced many theorists and philosophers both of the post-modern school and those outside of it. The interpretation of Foucault by contemporary theorists has lead many to adopt lines of thought considered Foucauldian and many to be labeled Foucaultist. Nonetheless Foucault and the subsequent development of his thought outside of his person greatly shaped the post-modern understanding of power.
To Foucault and those who subscribe to his theoretical developments power is an immutable force. One which not only exists everywhere but has no apparent origin. Rather than existing primarily through the operation of any such apparatus such as the state, power in the Foucauldian sense is reproduced in every instance and at every point in social interaction. Therefore while power has no real ‘origin’ it has many points at which it can be ‘resisted’ as it were:
By power… I do not understand a general system of domination exercised by one element or one group over another, whose effects… traverse the entire body social… It seems to me that first what needs to be understood is the multiplicity of relations of force that are immanent to the domain wherein they are exercised, and that are constitutive of its organization; the game that through incessant struggle and confrontation transforms them, reinforces them, inverts them; the supports these relations of force find in each other, so as to form a chain or system, or, on the other hand, the gaps, the contradictions that isolate them from each other; in the end, the strategies in which they take effect, and whose general pattern or institutional crystallization is embodied in the mechanisms of the state, in the formulation of the law, in social hegemonies. The condition of possibility of power… should not be sought in the primary existence of a central point, in a unique space of sovereignty whence would radiate derivative and descendent forms; it is the moving base of relations of force that incessantly induce, by their inequality, states of power, but always local and unstable. Omnipresence of power: not at all because it regroups everything under its invincible unity, but because it is produced at every instant, at every point, or moreover in every relation between one point and another. Power is everywhere: not that it engulfs everything, but that it comes from everywhere. 
Grasping this conception we may being to understand how the Foucauldian notions of power prompt largely individualist reactions to systems of power; in that, Foucault understands resistance to power to be primarily local and the existence of power largely a matter of specificity in dominating relationships. However, this is not the crude anti-humanism of previous epochs repackaged in the prose of contemporary theorists. Post-modernists do indeed believe humans can transform their social relationships including those of power. The difference being in the construction of this transformation as a whole of the instance rather than an instance of the whole; the universality of some power condition. This transformation not being like the Marxist conception of developing social relationships as this is seen as a ‘totality’ of social understanding but instead the local resistance to a specific form of power reproduced in a given instance:
I try to carry out the most precise and discriminative analyses I can in order to show in what ways things change, are transformed, are displaced. When I study the mechanisms of power, I try to study their specificity… I admit neither the notion of a master nor the universality of his law. On the contrary, I set out to grasp the mechanisms of the effective exercise of power; and I do this because those who are inserted in these relations of power, who are implicated therein, may, through their actions, their resistance, and their rebellion, escape them, transform them—in short, no longer submit to them. And if I do not say what ought to be done, it is not because I believe there is nothing to be done. Quite on the contrary, I think there are a thousand things to be done, to be invented, to be forged, by those who, recognizing the relations of power in which they are implicated, have decided to resist or escape them. From this point of view, my entire research rests upon the postulate of an absolute optimism. I do not undertake my analyses to say: look how things are, you are all trapped. I do not say such things except insofar as I consider this to permit some transformation of things. Everything I do, I do in order that it may be of use. 
At risk of making base analogies we should notice some similarities between Foucault’s conception of power and the neoplatonic understanding of the One to assist our understanding of the former. The latter mythical theory holds that the One is the source of all life and causality in the universe and nothing exists without it. However, the One is beyond any physical matter of being and all life in the universe is only a radiance of the One; reproducing the One but not the source thereof. In this way we see how Foucault’s power becomes similar to the One being that it is constantly reproduced in social instances but has no profound source in the material world. This also borders on the category of idealism as the existence and development of power seemingly occurs entirely outside of the material realm but acts upon it in the form of power relations and broader notions of individual and specific oppression.
In this sense we can understand Foucault to be primarily a nihilist, a characterization he never rejected. In actuality he described himself both as an irrationalist and as a nihilist greatly influenced by the would-be philosophical ‘father’ of postmodernism Friedrich Nietzche. A methodological form that categorically understands science and all other thought to be principally a reproduction of the same power; something that has meant a concrete break from the science of Marxism and the Enlightenment tools used in the development thereof.
In contrast to the postmodern theories of power exists the Marxist and principally Maoist understanding of the same. Here we understand power to be an expression of stratification in class society chiefly reproduced in the apparatus of the state. While power primarily extends from the ownership of the means of production this class power, the most fundamental form of power, has been channeled throughout the epochs into organs of state power being political supremacy of a class. Therefore the being of power takes form in the dialectic between the particular and the universal. Power exists transhistorically as a representation of that universal; the sum of history. Today we understand the transhistoric feature of power to take a particular form in the hegemony of the global capitalist class, its functionaries, institutions, and organs. Much of the work at anti-imperialism.com moves towards understanding the transformations and qualitative developments from particularity to particularity in the lineage of capital; understanding power as principally existing in the form of class dictatorship and the parallel struggle.
This understanding of power is critically important to the success of revolutionary movements around the world. The being of power should be understood as an object of struggle not as some invincible and unknowable feature of the human experience. The necessity of seizing power in opposition to vague and petty individualist notions of ‘anti-power’ and ‘counter-hegemony’.
The postmodern line is one of a romanticized individualism and privileged position. All thought comes stamped with the character of its class and the postmodern line of power is no different. Clearly, the aforementioned is not a weapon of emancipation for the oppressed and working peoples but tool cleverly used against them. A system of thought stamped with the reaction of petty bourgeois and privileged intellectuals who assure the working class their emancipation lies not in the destruction of their oppressors. Instead, they insist that the power which working people seek is unreachable and wholly immutable and put forth the political equivalent of DIY ‘liberation’.
Therefore their line cannot be considered compatible with a real revolutionary project or any movement for the conquest of political power. No doubt, some of Foucault’s work might be utilized if it can be articulated in a way that does not reject the science of dialectical materialism. JMP from MLM Mayhem has already spent some time on the issue. Regardless the discussion of power and its relationship to the Communist movement is one which deserves far more attention if we hope to actually change the world. How else can we change the world without first establishing the dictatorship of the Proletariat? The universal to the concrete expression of working class power.
The power to destroy the old world; to build anew.
 Foucault, Michel. 1976. History of Sexuality. Vol. I p. 121-22
 Foucault, Michel. 1976. Dits et Écrits. Vol. II p. 911-12