In Ajax all information like image, content or video whatever it may be all the data is retrieved in XMLHttp Request Object.
Basic Ajax example:
In this example I will explain you basic Ajax and PHP integration .
`id` INT NOT NULL AUTO_INCREMENT PRIMARY KEY ,
`category` VARCHAR( 10 ) NOT NULL ,
`title` VARCHAR( 255 ) NOT NULL ,
`link` VARCHAR( 255 ) NOT NULL
) ENGINE = MYISAM ;
After completing the form now run the script. While you selecting any option in the select box ajax will get the value of that particular category and send the value to the PHP. PHP will fetch the corresponding data from database. Again Ajax will get the output data from PHP and display it in html form. So without interrupting the user or browser we can show, edit or delete the database records.