A database is an organized collection of digital data that is available electronically, and can be manipulated, updated, stored, backed up, secured, and managed. The data is typically organized in a tabular format – in rows, columns, and tables – and indexed to make it easier to find information quickly, but the data is stored as files, not tables. The data is expanded and deleted as changes are made.
In a computer database there will usually be aggregations of files containing things like customer information, product information, sales information, etc. Access to the information is usually provided by a database management system (DBMS), which is software that offers users a way to interact with the data in the database, and can be used to control access to parts of the database. The DBMS controls the management of four key functions: data definition, data updating, data retrieval, and administration of users, security, data recovery, etc.
Relational databases were invented in the 1970s. They are made up of tables, each table holding at least one data category in a column, and each row holding a data instance for the categories in the columns. A relational database management system (RDBMS) is a type of database management software that was developed based on the relational model, and is still the most popular way to manage a database. The top RDBMS products include Microsoft SQL Server, Oracle Database, IBMDB2 and MySQL. Unlike DBMS applications, which store data as files, RDBMS applications store data in the form of tables.
Cloud databases have emerged in recent years, optimized for a virtual environment in a hybrid cloud, public cloud or private cloud. They offer the flexibility needed by many enterprises, allowing them to pay for storage capacity and bandwidth as needed, providing scalability on demand, and high availability. Cloud databases are often offered by SaaS providers.