What is Taxation?

Legal Definition
The Imposition of a tax; the act or process of imposing and levying a pecuniary charge or enforced contribution, ratable or proportioned to vuiue or some other standard, upon persons or property, by or on behalf of a government or one of its divisions or agencies, for the purpose of providing revenue for the maintenance and expenses of government The term "taxation," both in common parlance and in the laws of the several states, has been ordinarily used, not to express the idea of the sovereign power which is exercised, but the exercise of that power for a particular purpose, viz., to raise a revenue for the general and ordinary expenses of the government, whether it be the state, county, town, or city government. But there is another class of expenses, also of a public nature, necessary to be provided for, peculiar to the local government of counties, cities, towns, and even smaller subdivisions, such as opening, grading, improving in various ways, and repairing, highways and streets, and constructing sewers in cities, and cannis and ditches for the purpose of drainage in the country. They are generally of peculiar local benefit. These burdens have always, in every state, from its first settlement, been charged upon the localities benefited, and have been apportioned upon various principles; but, whatever principle of apportionment has been adopted, they have been known, both in the legislation and ordinary speech of the country, by the name of "assessments." Assessments have also, very generally, if not always, been apportioned upon principles different from those adopted in "taxation," in the ordinary sense of that term ; and any one can see, upon a moment's reflection, that the apportionment, to bear equally, and do substantial justice to ail parties, must be made upon a different principle from that adopted in "taxation," so called. Emery v. San Franeisco Gas Co., 28 Cal. 356. The differences between taxation and taking property in right of eminent domain are that taxation exacts money or services from individuals, as and for their respective shares of contribution to any public burden; while private property taken for public use, by right of eminent domain, is taken, not as the owner's share of contribution to a public burden, but as so much beyond his share, and for which compensation must be made. Moreover, taxation operates upon a community, or upon a class of persons in a community, and by some rule of apportionment; while eminent domain operates upon an individual, and without reference to the amount or value exacted from any other individual, or class of individuals. People v. Brooklyn, 4 N. Y. 419, 55 Am. Dec. 266.
-- Black's Law Dictionary
Legal Definition
An approximate compensation rendered by the inhabitants of a commonwealth or the owners of property situated within its borders for the protection afforded their persons or property by the government. See 56 Am. Dec. 523, note.
-- Ballentine's Law Dictionary