Although an infant's color vision is not as sensitive as an adult's, it is generally believed that babies have good color vision by five months of age. Most babies start crawling at about 8 months old, which helps further develop eye-hand-foot-body coordination.
A language tree, or family tree with languages substituted for real family members, has the form of a node-link diagram of a logical tree structure. Such a diagram contains branch points, or nodes, from which the daughter languages descend by different links.
A tree data structure can be defined recursively (locally) as a collection of nodes (starting at a root node), where each node is a data structure consisting of a value, together with a list of references to nodes (the children), with the constraints that no reference is duplicated, and none points to the root.he root node, at the top, has no parent. In computer science, a tree is a widely used abstract data type (ADT) or data structure implementing this ADT that simulates a hierarchical tree structure, with a root value and subtrees of children with a parent node, represented as a set of linked nodes.