A system intended for easily organizing, storing and retrieving large amounts of data, is called a database. In other words, a database holds a bundle of organized data (typically in digital form) for one or more users. Databases, often abbreviated DB, are classified according to their content, such as document-text, bibliographic and statistical. But, a DBMS (Database Management System) is actually the whole system used for managing digital databases which allows storage of database content, creation/maintenance of data, search and other functionalities. In today’s world a database itself is useless if there is no DBMS associated with it for accessing its data. But, increasingly, the term Database is used as shorthand for Database Management System.
A Database may contain different levels of abstraction in its architecture. Typically, the three levels: external, conceptual and internal make up the database architecture. External level defines how the users view the data. A single database can have multiple views. The internal level defines how the data is physically stored. The conceptual level is the communication medium between internal and external levels. It provides a unique view of the database regardless of how it is stored or viewed. There are several types of databases such as Analytical database, Data warehouses and Distributed databases. Databases (more correctly, relational databases) are made up of tables and they contain rows and columns, much like spreadsheets in Excel. Each column corresponds to an attribute while each row represents a single record. For example, in a database, which stores employee information of a company, the columns could contain employee name, employee Id and salary, while a single row represents a single employee.
DBMS, sometimes just called a database manager, is a collection of computer programs that is dedicated for the management (i.e. organization, storage and retrieval) of all databases that are installed in a system (i.e. hard drive or network). There are different types of Database Management Systems existing in the world, and some of them are designed for the proper management of databases configured for specific purposes. Most popular commercial Database Management Systems are Oracle, DB2 and Microsoft Access. All these products provide means of allocation of different levels of privileges for different users, making it possible for a DBMS to be controlled centrally by a single administrator or to be allocated to several different people. There are four important elements in any Database Management System. They are the modeling language, data structures, query language and mechanism for transactions. The modeling language defines the language of each database hosted in the DBMS. Currently several popular approaches like hierarchal, network, relational and object are in practice. Data structures help organize the data such as individual records, files, fields and their definitions and objects such as visual media. Data query language maintains the security of the database by monitoring login data, access rights to different users, and protocols to add data to the system. SQL is a popular query language which is used in Relational Database Management Systems. Finally, the mechanism that allows for transactions help concurrency and multiplicity. That mechanism will make sure same record will not be modified by multiple users at the same time, thus keeping the data integrity in tact. Additionally, DBMSs provide backup and other facilities as well.
Difference between DBMS and Database
A database is a collection of organized data and the system that manages a collection of databases is called a Database Management System. The database holds the records, fields and cells of data. The DBMS is the tool used to manipulate the data inside the database. However, the term database is increasingly used as shorthand for Database Management System. To make the distinction simple, consider and operating system and the individual files stored in the system. Just like you need an operating system to access and modify files in the system, you need a DBMS to manipulate databases stored in the database system.