What are the two major components of SQL and what function do they serve?

The Data Definition Language (DDL). This component of the SQL language is used to create and modify tables and other objects in the database. For tables there are three main commands:

CREATE TABLE tablename to create a table in the database

DROP TABLE tablename to remove a table from the database

ALTER TABLE tablename to add or remove columns from a table in the database.

The Data Manipulation Language (DML) component of the SQL language is used to manipulate data within a table. There are four main commands:

then,

SELECT to select rows of data from a table

INSERT to insert rows of data into a table

UPDATE to change rows of data in a table

DELETE to remove rows of data from a table