What is Structured Query Language (SQL)?
Structured Query Language (SQL) is a sql database free standardized programming language for managing relational databases and performing various operations on the data within them. Originally created in the 1970s, SQL is frequently used not only by database administrators, but also by developers writing data integration scripts and data analysts looking to set up and run analytical queries.

The term SQL is pronounced ess-kew-ell or sequel.

SQL is used for the following purposes:

Modify the database table and index structure;
Add, update and delete rows of data; and
Retrieve a subset of information from relational database management systems (RDBMSes) -- this information can be used by transaction processing, analytical applications, and other applications that need to communicate with relational databases.
SQL queries and other operations take the form of commands written as statements and aggregated into programs that enable users to add, modify, or retrieve data from database tables.

A table is the most basic unit of a database and consists of rows and columns of data. A single table holds records, and each record is stored in a row of the table. A table is the most commonly used type of database object, or a structure that holds or references data in a relational database. Other types of database objects include:

A view is a logical representation of data collected from one or more database tables.
Indexes are lookup tables that help speed up database lookup functions.
A report consists of data retrieved from one or more tables, usually a subset of the data selected based on search criteria.
Each column in the table corresponds to one type of data—for example, customer names or addresses—and each row contains cross-column data values.

Relational databases are relational in that they consist of interrelated tables. For example, a SQL database for customer service could have one table for customer names and addresses, while other tables contain information about specific purchases, product codes, and customer contact information. Tables used to track customer contacts typically use unique customer identifiers called keys or primary keys to refer to customer records in separate tables used to store customer data such as name and contact information.

After its emergence in the late 1970s and early 1980s, SQL became the de facto standard programming language for relational databases.