To specify a range of test you can use BETWEEN operator.
Example of BETWEEN:
SELECT * FROM users WHERE age BETWEEN 18 AND 55;
Here below 18 and above 55 aged user will be eliminated.
For your own understand you can give an alias name to a column while getting the data from a table. This is called alias.
SELECT first_name AS `name` FROM users WHERE age BETWEEN 18 AND 55;