Office Politics is simply how power gets worked out on a practical, day-to-day basis.
Office politics "is the use of one's individual or assigned power within an employing organization for the purpose of obtaining advantages beyond one's legitimate authority. Those advantages may include access to tangible assets, or intangible benefits such as status or pseudo-authority that influences the behavior of others. Both individuals and groups may engage in Office Politics."
Office politics differs from office gossip in that people participating in office politics do so with the objective of gaining advantage, whereas gossip can be a purely social activity. However, both activities are highly related to each other.
Office politics also refers to the way co-workers act among each other. It can be either positive or negative although for most of us 'abnormals' it's negative!