A fictional faction of benevolent sentient alien robots from the planet Cybertron. They are usually the main protagonists in the fictional universe of Transformers.
In all but one Transformer story, the "Heroic Autobots" are opposed by the "Evil Decepticons", their main antagonists in Transformers.
Both Autobots and Decepticons are sentient humanoid alien robots that can transform into machines, vehicles and other familiar mechanical objects. They are typically represented by the red facial insignia they all wear. Primarily, Autobots have blue eyes, while their enemy Decepticons have red eyes.
Autobots often turn into regular cars, trucks, or other road vehicles but some are aircraft, military vehicles, communication devices, weapons, and cyborg animals. Some can even transform into humans; they'd be classified as pretenders. Most of the Autobot groups' names have the suffix "-bot" in them.
In Japan, the Autobots are called Cybertrons (サイバトロン, Saibatoron?) except in the live-action film series and Transformers Animated, where they are referred to as Autobots (オートボット, Ōtobotto?). The Maximals from Transformers: Beast Wars are also known as Cybertrons in Japan, but in North America they are called Maximals and are descendants of the Autobots. In Italy, they are called Autorobots. The Autobot symbol is also referred to as an "Autobrand" in issue #14 of the Marvel Comics series.
In the Michael Bay live action films as well as in the new CGI animated series (Transformers Prime), the title Autobots is explained to be the short version of the title Autonomous Robotic Organisms.