In the hierarchical model, the basic logical structure is represented as an upside-down tree.
This is so because the structure starts at the top with groups or levels of higher hierarchy and these are further subdivided into groups of lower hierarchy, which is why the structure becomes wider as you move from top to bottom.
In the hierarchical model, the basic logical structure is represented as an upside-down tree. A hierarchical model is a type of data model, it is a tree-like model in which lower levels/groups are sorted under a hierarchy of higher-level unit (like sorting the staffs of a department in a company under the head of department). The levels are connected to one another through links. A simple pictorial representation of the hierarchical data model is shown in the attachment
