Q.What is a DBMS? State any four functions performed by a DBMS.

A DBMS is the software that manages a database; this question asks for its definition and its main jobs.

A Database Management System (DBMS) is software that enables users to create, store, organise, retrieve, update and manage the data in a database. It acts as the interface between the user (or an application program) and the actual data stored on disk, handling all the low-level details so the user only has to say what they want.

Four functions performed by a DBMS (any four):

1. Data definition — defining the structure of the data: the tables, their columns, and the data type of each column.
2. Data storage and retrieval — storing data on disk and fetching exactly the records the user asks for.
3. Data manipulation — inserting new data, updating existing data and deleting unwanted data.
4. Data security — controlling who may see or change which data through user accounts, passwords and permissions. (Other valid functions: data integrity — enforcing validity rules so only correct data is stored; backup and recovery; and concurrent access control — letting many users work at once without conflict.)
   ✓Final answer

   A DBMS is software that lets users create, store, retrieve, update, secure and manage the data in a database. Four functions: data definition, data storage and retrieval, data manipulation, and data security (also data integrity, backup/recovery, concurrency control).

A DBMS is the software, not the data itself — do not define it as 'a collection of data' (that is the database). When four functions are asked for, list exactly four distinct ones rather than repeating the same idea in different words.