Editing Data model (section)

=== Data structure ===
{{Main|Data structure}}
[[File:Binary tree.svg|thumb|240px|A [[binary tree]], a simple type of branching linked data structure]]
A data structure is a way of storing data in a computer so that it can be used efficiently. It is an organization of mathematical and logical concepts of data. Often a carefully chosen data structure will allow the most [[algorithmic efficiency|efficient]] [[algorithm]] to be used. The choice of the data structure often begins from the choice of an [[abstract data type]].

A data model describes the structure of the data within a given domain and, by implication, the underlying structure of that domain itself. This means that a data model in fact specifies a dedicated ''grammar'' for a dedicated artificial language for that domain. A data model represents classes of entities (kinds of things) about which a company wishes to hold information, the attributes of that information, and relationships among those entities and (often implicit) relationships among those attributes. The model describes the organization of the data to some extent irrespective of how data might be represented in a computer system.

The entities represented by a data model can be the tangible entities, but models that include such concrete entity classes tend to change over time. Robust data models often identify [[abstraction]]s of such entities. For example, a data model might include an entity class called "Person", representing all the people who interact with an organization. Such an [[abstract entity]] class is typically more appropriate than ones called "Vendor" or "Employee", which identify specific roles played by those people.

<gallery class="center">
Image:Array of array storage.svg|Array
Image:HASHTB08 en.svg|[[Hash table]]
Image:Singly linked list insert after.png|[[Linked list]]
Image:Data stack.svg|[[Stack (data structure)]]
</gallery>