radial drawing

A layout style where the nodes are placed radially around a root node.

recursive

The fact that the same mechanism that is applied to a large structure is also applied to its substructures. A recursive layout that is applied to a nested graph is also applied to each subgraph.

ring

A type of network topology where the nodes are arranged in a circular configuration.

root

In a tree, the root is only one specified node. In a directed graph, a root is a node that has no incoming links.