Power drill vs. electric drill vs. electric screwdriver

Is there a commonly-accepted distinction between the either power drill or electric drill and electric screwdriver, whether semantic, dialectic, sociolectic, or something else? — For myself, power drill seems most unmarked, followed by electric drill and then electric screwdriver. To me, they all mean the same thing, namely a gun-like device which accepts bits of various types, either for drilling or "screwdriving". However, there have been times (admittedly mostly by non-native speakers of English yet also by some native speakers) when I ask:

Me: Have you got a power drill?

Someone else: No, I'm sorry.

Me: (surprised) Well, I can't screw this in by hand: The material is just too hard.

Someone else: I think I might I have an electric screwdriver somewhere.

Me: (confused) Okay... thanks.

An electric screwdriver implies the simple ability to drive lightweight screws into pre-tapped holes, without the speed and horsepower required to drill holes (or even to drive hardier, self-tapping screws into a solid wood stud) which one would find with an electric drill. A power drill probably refers to an electric drill which is corded, and runs on electricity from the wall, with even more torque.

Torque is a measurement of twisting force, and the amount of torque that a tool produces is an indicator of the tasks it's capable of accomplishing. In general, lightweight electric screwdrivers tend to use less powerful, lower voltage motors than many cordless drills, so they may not be up heavy-duty tasks such as driving long lag screws into hardwood. Cordless drills with 18-V or 20-V motors, on the other hand, can handle just about any screw-driving task.

• from http://www.ehow.com/about_6504699_electric-screwdriver-vs_-drill.html

I've used all three professionally, and am a native speaker.

A power drill or electric drill (the terms are interchangeable in most contexts) has a gripping chuck to hold the bit. There are various kinds of bit, each for a specific task, many having shanks of different sections. Most drill holes but there are also screwdriver bits of various types.

If the drill has variable speed and/or torque settings the drill can be used as a screwdiver by inserting a screwdriver bit into the chuck, however most drills do not have a reverse function so they will only tighten right-handed screws and loosen left-handed ones. An electric or power screwdriver, on the other hand, has no chuck, only a socket to accept screwdriver bits. It should, however, have a reverse function and, usually, variable speed.

Electric drills and electric screwdrivers are different tools but there is some overlap in their function.