<P> In a mathematical context (in graph theory), the general terminology used is different . </P> <P> Most hierarchies use a more specific vocabulary pertaining to their subject, but the idea behind them is the same . For example, with data structures, objects are known as nodes, superiors are called parents and subordinates are called children . In a business setting, a superior is a supervisor / boss and a peer is a colleague . </P> <P> Degree of branching refers to the number of direct subordinates or children an object has (in graph theory, equivalent to the number of other vertices connected to via outgoing arcs, in a directed graph) a node has). Hierarchies can be categorized based on the "maximum degree", the highest degree present in the system as a whole . Categorization in this way yields two broad classes: linear and branching . </P> <P> In a linear hierarchy, the maximum degree is 1 . In other words, all of the objects can be visualized in a lineup, and each object (excluding the top and bottom ones) has exactly one direct subordinate and one direct superior . Note that this is referring to the objects and not the levels; every hierarchy has this property with respect to levels, but normally each level can have an infinite number of objects . An example of a linear hierarchy is the hierarchy of life . </P>

The two broad types of control structures is branching and