Generally Utopia means an unreachable ideal of an idea, no matter if you're talking about society, believes or an intention. Looking at it from a more philosophical point of view, Utopia means the ideal state of the human society, usually very peaceful.
The name Utopia comes from the 1516 published novel "utopia" by Thomas More. Living under Henry the VIII he published his satirical novel "utopia" in which he portrayed a society based upon collective property, similar to the idea of communism. Though he only wanted to criticise the social standards in England at this time the king let More decapitate in 1535.
The models for Moore's work have been antique writing from Plato or from the middle ages Joachim von Fiore's works. So the first real so called Utopian novels were written at the time of the Renaissance, not only by More, but also by Giovanni Domenico Campanella (The Sun Nation) or more famous Francis Bacon (Nova Atlantis). Basing on theses novels developed through out the 17th and 18th century in England and French a literary class that criticised the society compared to the possible ideal which often seemed to have a timeless character. Inseparable linked to the Utopian illusion was the ideal combination of the religious life and the worldly life in harmony with the gospel.
Since the beginning of the 19th century many literary utopian vision have a direct link to real events of that time. Urged by a big optimism in a better future most of the utopian stories are now settled somewhere, far in the future, while they were settled only in a different country before. Because of technical and scientifically progress the people hoped for an end of all the lacks of food and wealth and for an end of the suppression.
Writers like R. Owen or C. Fourier thought that the only possibility to take all advantages of the technical progress was to put an end to property of the single. At the same time the first non technical utopian visions came up, getting back to the roots, living very humble in harmony with the nature and return to our ancient ways of living.
In the 20th century more and more negative utopian visions caused by the technical progression or totalitarian suppression came up. Just to list some of them: "Brave New World" by Aldeous Huxley, "1984" by George Orwell, "Us" by Jewgenij Iwanowitsch Samjatin
Still Science Fiction is linked very tight to the theme of Utopia!