On Star Trek, Commander Data is not human, he's an android, not a cyborg. I thought cyborgs looked human (like terminator) but droids looked more robot than human (like C3PO).
Is this an official thing like starships and spaceships, or does it vary from one SciFi work to another?
Robot is any artificial thing made to do work. Wiki defines it as a "mechanical or virtual intelligent agent that can perform tasks automatically or with guidance, typically by remote control". It's a very generic term.
Anything can be a robot - from an industrial robot used on an assembly line (pretty much just an arm with a CPU) to human-like android to a spaceship with a computer brain - real (e.g. Buran) or artificial (e.g. V'ger). Though in latter case, they are rarely referred to as "robots" despite fitting the definition 100%.
Android (from Late Greek androeidēs - manlike; see andro- , -oid) is a robot resembling a human being (frequently, though not necessarily a very close, ideally undistinguishable resemblance is implied).
Examples include Star Trek's Data, Star Wars' C3PO (to an extent), or Blade Runner androids.
A cyborg, short for "cybernetic organism", is a being with both biological and artificial (e.g. electronic, mechanical or robotic) parts.
A cyborg can be in ANY form, human like or not (in the former case, a cyborg is also classified as "android").
Android can be made using any technology. It can be entirely artificial (like Star Trek's Data) or part biological (which makes it a cyborg).
A robot is a generic term - anything can be a robot. All androids are robots. As interesting aside, the original robots (from Karel Čapek's play R.U.R. - Rossum's Universal Robots) were meant to be human-like, e.g. androids, though the term wasn't created at that point yet.
As usual, a given SciFi author can screw up - intentionally or through ignorance - any definitions and call anything anything he wants. As an example, R2-D2 from Star Wars is called a droid - derivative from "Android" - despite being in the form of trashcan post office box, instead of a human shape.
A cyborg is at least partially organic (the "org" part). So a human with grafted cybernetic components is a cyborg. Like Commander Data, The Terminator is NOT a cyborg, as he's robot all the way through. Robocop is a cyborg, being built on a biological human frame.
An android is a robot in the form of a human ("andro" being greek for "man"). Data and Arnold are both androids.
R2D2, while referred to as a "droid", is NOT an android. Whatever is greek for "trash can", he's a that-oid.
Edit: NOT C3PO!! Bad geek! No comic book!
Despite some conventional differences, both bio-robot and cyborg can be used synonymously. The differences are further muddied by terms like robo-animals, semi-organic robots, or a wide range of other terms used by various authors and settings.
While most of us can agree that a human with robot parts is a cyborg, and a robot with out living parts is an android, the T-800 (AKA: Cyberdyne Systems Model 101) from the Terminator Series seems to be the fringe case that people here don't agree about, because it is a robot grafted with human parts rather than the other way arround.
Many experts would argue it is a bio-robot because of the computer control system, but the Terminator movie itself disagrees:
Kyle Reese: He's not a man - a machine. A Terminator. A Cyberdyne Systems Model 101.
Sarah Connor: A machine? Like a robot?
Kyle Reese: Not a robot. A cyborg. A cybernetic organism.
Since this is scifi.se I would argue that cyborg is the right usage case for something like the T-800 due to its usage in canon, but on if this were biology.se, I would argue that bio-robot is the more correct term due to its usage in various real world contexts. In another setting like Warhammer 40k, something like a T-800 would more rightly be called a servitor or a semi-organic robot.
Another Fringe case are replicants. In the book "Do Androids Dream of Electric Sheep?" they called artificial humans Androids. However, in this case, the franchise latter changed the term to Replicants to avoid confusion when they produced the Blade Runner movies. Another similar case would be the Humanoid Cylons from the Battlestar Gallactica reboot. Here they addressed artificial humans as robots, replicants, or skin jobs despite being virtually indistinguishable from their organic counterparts. They only called the more obviously mechanical Cylons androids. So all in all, it seems the trend of the scifi community is to get away from using the term android to include biological robots, and use the term replicant instead.
Ultimately, these are all pretty new words in the English language, and their definitions and boundary are still fuzzy at best. Real world developments in cybernetics are also having retroactive impacts on the perception of these words. In court cases, arguments have been made about if everything from a person's pacemaker, removable prosthetics, or even cellphones should legally be considered part of their body or property with some claimants saying that all modern people are already cyborgs because we have become so reliant on computers to "function properly".
androids can still have skin on them like in dragon ball z ,Aliens or some early prototypes of the T-series robots which had rubber skin but they can not have any blood etc or they would be classed as cyborg
the only difference with Arnolds T was he had blood in his skin which makes him cyborg
Robots are anything mechanical with a CPU think of them as the mechanical version of brainwashed zombies puppets if you will
Droids are as you see in star wars C3PO R2-D2 etc these are mechanical robots with an AI that is self aware now yes there is a little debate because the battle droids are commanded through ships etc but for now they are still classed as droids
There is much to learn
cyborgs are just people with robot parts and they can live without. were as an android is a being made from both organic and machine material that they can not live with out
