This many-sided word, like its equivalents in the modern versions of the Bible, is used to translate the Hebrew "dor" and "toledah" (the latter found only in the plural). The primary meaning of "dor" is "period"; the secondary, the period bounded by the life of a man or of a single family. Thus "dor" signifies generations, or ages, of men in the past or future; it also designates the men who live in any special period or age (see especially Ps. cxlv. 4; Eccl. i. 4). From this idea of men regarded as a group bound together by relationship a transition is made to men of any particular time taken as a class connected only by contemporaneousness. Thus in "a generation that curseth its father" (Prov. xxx. 11) the class character is so strong that the persons described are spoken of throughout as a single unit.
In "toledot," on the other hand, the idea of descent by birth and family relationship gives its special force to the translating term. Thus "generations" in Gen. x. 32 means a genealogical succession of families; in Num. i. 20, genealogical divisions by parentage. A secondary and very important usage may be seen where "generations" means the history in the form of a genealogical account of any set of people along with their descendants (Gen. v. 1). All early history began with genealogical lists, and even the process of creation of heaven and earth is viewed in Gen. ii. 4 as a genealogical history. The word "toledot" is found mostly in the Hexateuch, and there only in the Priestly Code.