Database is a collection of data which are logically related. Database, as used in computer science, is well defined and structured collection of data which are stored digitally in computer system. They are designed to be easily stored and retrieved using database queries, a set of computer codes translated into a language that the database system can understand.  The computer program that is employed to manage and query a database is called a database management system (DBMS).

There are many different ways to model data structure inside the database. Some of these models include Flat model, Hierarchical model, Network model, Relational model
Object database models and Post-relational database models.

The Flat model, also called table model, is made up of single, two-dimensional array of data elements. All members of a certain column are assumed to contain similar values while all the member of a rows are assumed to have relationships with one another. Flat models are no longer popular today because they hard to manage when the volume of data rises.

The Hierarchical model organizes data into a tree-like structure. The model would have a single upward link in each record in order to describe the nesting. It contains a sort field used for keeping the records in a particular order in each of the list in the same level.

Network model stores records linking with other records as the name implies. Pointers, which can be node numbers or disk addresses, are used to track all the associations within the database.

Relational model is today the most widespread model used in database implementations. The relational model deals with table, columns and rows. The table contains information about an entity, which is a representation of any thing of interest in the real life counterpart. The column contains all attributes pertaining to the entity.

The term relational refers to the fact that various tables in the database have relation to other tables and programmatic algorithms make it easy to insert, update, delete and all other operations on different tables without sacrificing data quality and integrity. Databases implemented using the relational mode as managed by a relational database management system (RDBMS).

Object database models are newer types of models under the object-oriented paradigm. This model makes an attempt to bring together the database world and the application programming.

The object database model tries to avoid computation overhead by creating reusable objects based on a class or template. This model attempts to introduce into the database world some of the main concepts of object oriented programming such as encapsulation and polymorphism.

The Post-relational database model attempts to incorporate relations while not being constrained by the information principle which requires all information to be represented by data values in a relation.

Some of the products which employ the post-relational database model often use a model which predates the relational model. Some of these products include PICK (aka MultiValue) and MUMPS.

Some of the database internal considerations include aspects related to Storage and Physical Database Design, Indexing, Transactions and concurrency, Replication and Security.

Databases are ubiquitous in the world of computing with and they are used in a lot of applications that spans virtually the entire range of computer software. They are the preferred data storage methods for large multi-user applications and environments where large chunks of data are being dealt with. Databases have become an integral part of many implementations of web servers. With the fast rise of e-commerce websites today, databases are becoming indispensable tools for internet business.

Large enterprise data warehouses cannot run without the use of databases. This sophisticated repository of data needs to be managed effectively by a database management software application.