Successor to hereditary title, office or like, in case of the heritage being indivisible, goes to one person at a time. There are also other sorts of order of succession than hereditary succession (such as line of non-hereditary succession to democratic state offices).
The hereditary line of succession may be limited to heirs of the body, or may pass also to collateral lines, in case of extinction of heirs of the body, depending on the succession rules. These concepts are in use in English inheritance law.
Main concepts for hereditary succession are usually either heir male or heir general - see further primogeniture (agnatic, cognatic, and also equal).
Certain types of property pass to a descendant or relative of the original holder, recipient or grantee according to a fixed order of kinship. Upon the death of the grantee, a designated inheritance such as a peerage, or a monarchy, passes automatically to that living, legitimate, natural relative of the grantee who is most senior in descent, regardless of the relative age; and thereafter continues to pass to subsequent successors of the grantee, according to the same formula, upon the death of each subsequent heir.
Each person who inherits according to this formula is considered an heir at law of the grantee and the inheritance may not pass to someone who is not a natural, lawful descendant or relative of the grantee.
Collateral kin, who share some or all of the grantee's ancestry, but do not directly descend from the grantee, may inherit if there is no limitation to heirs of the body.