The Transformers brand is the umbrella term for all products or media involving the transforming alien robots from the planet Cybertron developed in 1984 by Hasbro and Marvel Entertainment (then Marvel Entertainment Group) under license from Takara, including any lineal descendants thereof.
Transformers has been in almost continuous circulation since its launch 34 years ago, never absent from American toy shelves for more than 18 months. Unlike many 80s brands relaunched in the 2000s to capitalize on the 20-year nostalgia cycle, the Transformers brand is truly evergreen. As a result it has grossed Hasbro more than $1 billion USD since its launch.
Spelling and capitalization
In the various Transformers logos used over the decades, the word is often split across two lines, with no hyphen, thus suggesting (by the rules of normal punctuation) that it's two words: "Trans Formers". Other logos are explicitly bicapitalized: "TransFormers". Further, when Hasbro is being strict about the word's trademark status, they write it in allcaps: "TRANSFORMERS".
Despite all that, it's generally agreed that the correct rendering is "Transformers", and that's the way it appears in this wiki.