A database is a computerised system that makes it easy to search, select and store information. Databases are used in many different places. Data is organised into rows, columns and tables, and it is indexed to make it easier to find relevant information. Data gets updated, expanded and deleted as new information is added. Databases process workloads to create and update themselves, querying the data they contain and running applications against it.
Relational Database - The relational database was invented in 1970 by E.F. Codd at IBM. It is a tabular database in which data is defined so that it can be reorganised and accessed in a number of different ways.
Relational databases are made up of a set of tables with data that fits into a predefined category. Each table has at least one data category in a column, and each row has a certain data instance for the categories which are defined in the columns.
SQL is the standard user and application program interface for a relational database. Relational databases are easy to extend, and a new data category can be added after the original database creation without requiring that you modify all the existing applications.
Distributed Database - A distributed database is a database in which portions of the database are stored in multiple physical locations, and in which processing is dispersed or replicated among different points in a network.
Cloud Database - A cloud database is a database that has been optimised or built for a virtualized environment, either in a hybrid cloud, public cloud or private cloud. Cloud databases provide benefits such as the ability to pay for storage capacity and bandwidth on a per-user basis, and they provide scalability on demand, along with high availability.
Object Oriented Database - Items created using object-oriented programming languages are often stored in relational databases, but object-oriented databases are well-suited for those items.
An object-oriented database is organised around objects rather than actions, and data rather than logic.