What is MySQL's CREATE VIEW command for?

CREATE VIEW creates an object of type VIEW in its database.

A View is a transformation on top of one or more tables that behaves like a table. It is usually read-only (you can not insert, change, or delete lines from it).

Example:

CREATE VIEW MinhaView AS
SELECT COLUNA2, COLUNA4, COLUNA6 
FROM TABELA 
WHERE COLUNA1 = 1;

You can select data directly over View after creation:

SELECT * FROM MinhaView;

The result will be equivalent to the SELECT that is part of the View body.

EDIT

Example asked for comment:

CREATE VIEW MinhaView2 AS
SELECT CONCAT(NOME, ' ', SOBRENOME) AS NOME_COMPLETO, COLUNA2, COLUNA3, COLUNA4
FROM TABELA_COM_NOME;

Serves to create a 'read-only table' / virtual table that is based on queries. It can work as a shortcut for long queries.

Instead of putting this query in multiple places in the code

SELECT p.nome, c.categoria_descricao, t.tipo_descricao FROM produtos as p
INNER JOIN categorias as c ON  p.id_categoria = c.id_categoria
INNER JOIN tipo as t ON  p.id_tipo = t.id_tipo

You could create a view to bring the description and product type, simplifying your call.

CREATE view produto_simplificado as
SELECT p.nome, c.categoria_descricao, t.tipo_descricao FROM produtos as p
INNER JOIN categorias as c ON  p.id_categoria = c.id_categoria
INNER JOIN tipo as t ON  p.id_tipo = t.id_tipo

then you would just call it that way

SELECT * FROM produto_simplificado

A quote taken from the IMaster post ( Working with VIEWS in MYSQL )

  

A View is an object that belongs to a database, defined   based on SELECT statements, returning a certain   data from one or more tables. These objects are   sometimes referred to as "virtual tables", formed from other   tables that are called "based tables" or   Views. And in some cases, Views are upgradeable and can be   statement INSERT, UPDATE, and DELETE, which actually modify your   "Based tables".

     

The benefits of using Views, in addition to those already highlighted, are:

     

A View can be used, for example, to return a value   based on a record identifier; It can be used to   promote restrictions on data to increase data security and   define table-level and column-level access policies. Can be   configured to display different columns for different users   the database; It can be used with a set of tables that   can be joined to other sets of tables with the use of   JOIN's or UNION.

A View is a SELECT query that gets saved in the database for later use. When you need View data in any context, just use the View's name, which will be as a sub-SELECT at the point where the View name is used.