A hierarchical model uses a tree-like structure to represent the data, with a single parent, or a root, in each record. The record corresponds to a single table, holding information about a particular subject, and is connected to other records using links. A specific order is used to sort sibling records.

The following diagram shows a typical hierarchical database model. As shown in the following diagram, each branch of the hierarchy illustrates a number of related records. A relationship in a hierarchical database is shown by parent/child. A user can access data within this model by starting at the root table and working down through the tree, to the target data. While this model stores the structure in a tree-down fashion, it is very important for a person to know the structure of the model, in order to access the data. For example, in order to access Labs data, as shown in the following diagram, a user has to understand the entire model: