Cybertron (サイバトロン, Saibatoron) is the home planet of the Transformers, Autobots and Decepticons alike even. Cybertron is (almost always) a shining metal, technological world; a planet of towering future cities without end and vast metallic plains, spiraling metal mountains and bottomless neon-lit chasms. Battling over the planet's resources, the AllSpark, and control of Cybertron is frequently the motivation for, or origin of, the Transformers' aincent, historical, but epic war, the Great War have started.
Cybertron is orbited by three "near-Cybertron" objects: Moon Bases One and Two and the Trypticon Asteroid Belt Station, each on opposite hemispheres of the planet (presumably the Iaconian and Kaonian sides). Beyond the moons and asteroid belt floats an ancient space bridge generator, the long-abandoned interstellar transportation system that once connected Cybertron to other Transformer colony homeworlds such as, Velocitron, Animatron, Gigantion, and so on.
One day, as the nameless miners resorted to gladiatorial combat as an outlet for their misery, a champion named Megatron rose to seize the title of Prime for himself. Unwittingly, his Iaconian ally was appointed Optimus Prime instead, and their anti-caste movement became a war for Cybertron's future; the beginning of the Great War. The AllSpark was lost to space, and whole regions of the planet were laid waste, prompting the Autobots to evacuate on the Ark. Megatron and his chosen Decepticon forces left on the Nemesis, leaving Shockwave and the unchosen Decepticons to stay behind and continue the battles with the Autobots that were also stayed behind on the planet under the command of Ultra Magnus.
In an interesting turn of events that led the Decepticon ancestors to thier defeat. Autobot mastery of the newly designed space bridge technology, and their leader's strategic relocation of the AllSpark led to ultimate victory, the future descendants of Decepticons have been driven entirely from the planet and a Cybertron where an entire generation has seen neither armor-plating nor transistor of a Decepticon. According to Sentinel Prime, it doesn't rains on Cybertron.