Terminologies used in Trees

Terminologies used in Trees

• Root – The top node in a tree.
• Parent – The converse notion of child.
• Siblings – Nodes with the same parent.
• Descendant – a node reachable by repeated proceeding from parent to child.
• Ancestor – a node reachable by repeated proceeding from child to parent.
• Leaf – a node with no children.
• Internal node – a node with at least one child.
• External node – a node with no children.
• Degree – number of sub trees of a node.
• Edge – connection between one node to another.
• Path – a sequence of nodes and edges connecting a node with a descendant.
• Level – The level of a node is defined by 1 + the number of connections between the node and the root.
• Height of tree –The height of a tree is the number of edges on the longest downward path between the root and a leaf.
• Height of node –The height of a node is the number of edges on the longest downward path between that node and a leaf.
• Depth –The depth of a node is the number of edges from the node to the tree's root node.
• Forest – A forest is a set of n ≥ 0 disjoint trees.