Gordon Shumway writes:

On Fri, 19 Jul 2013 19:34:13 -0700 (PDT), leza wang
wrote:

Hi all
In this video minute (0:40) the person is using machine to
screw. What this machine is? a drill with special head or what? I
have a drill but not cordless and i am thinking to use it as a screw
driver to screw a big board for my front house, or do I need special
device? Thanks

https://www.youtube.com/watch?v=fkOVc9FtozA

The tool you are referring to is a battery powered drill/driver. It
can be used to drill holes or drive screws when the proper bit is
inserted in the chuck. The tool being used in the video is a Dewalt
drill/driver similar to this one:

http://www.dewalt.com/tools/cordless...s-dc759ka.aspx

DO NOT use a corded drill to try to drive screws! If you are not
familiar with this operation you can easily hurt yourself.

Corded drills don't have clutches to adjust the torque for that
application. Even if it is variable speed drill it is very difficult
to control the speed for driving screws. They are not intended for
that job.

I have a Ryobi corded drill.

With a clutch.

I've driven thousands of screws with it.

--
Dan Espen