Node (computer science)

A node is a basic unit of a data structure, such as a linked list or tree data structure. Nodes contain data and also may link to other nodes. Links between nodes are often implemented by pointers. Nodes are often arranged into tree structures. A node represents the information contained in a single data structure. These nodes may contain a value or condition, or possibly serve as another independent data structure. Nodes are represented by a single parent node. The highest point on a tree structure is called a root node, which does not have a parent node, but serves as the parent or 'grandparent' of all of the nodes below it in the tree. The height of a node is determined by the total number of edges on the path from that node to the furthest leaf node, and the height of the tree is equal to the height of the root node. Node depth is determined by the distance between that particular node and the root node. The root node is said to have a depth of zero. Data can be discovered along these network paths. An IP address uses this kind of system of nodes to define its location in a network. Child: A child node is a node extending from another node. For example, a computer with internet access could be considered a child node of a node representing the internet. The inverse relationship is that of a parent node. If node C is a child of node A, then A is the parent node of C. Degree: the degree of a node is the number of children of the node. Depth: the depth of node A is the length of the path from A to the root node. The root node is said to have depth 0. Edge: the connection between nodes. Forest: a set of trees. Height: the height of node A is the length of the longest path through children to a leaf node. Internal node: a node with at least one child. Leaf node: a node with no children. Root node: a node distinguished from the rest of the tree nodes. Usually, it is depicted as the highest node of the tree. Sibling nodes: these are nodes connected to the same parent node. Another common use of node trees is in web development.