Cyberpunk is usually set in the near future, one that we can invision in the next 25 to 100 years. Cyberpunk worlds tend to be very dark and nasty for the characters involved, but there is usually a privileged class for whom life is very good. The same technology that makes life good for the elite, makes oppression and survellince the norm for the rest.
Corporations are viewed as the bad guys, along with the people who run them. The political system and economic system are viewed as oppressive and soul killing. People who want to live the good material life have to give up freedom of behavior. The gap between rich and poor is vast and growing. Crime is rampant in the poor parts of town, and almost unheard of in the rich gated communities. Social mobility is limited. One could look at Victorian England and add modern Japanesse tech to get a feel for the world.
Computer technology is at the heart of the cyberpunk theme. It is computers, and other similar technology that make the world so strange.
Co-Dominion Series
The Co-Dominion series is military science fiction set in a space going world that is ruled by the power elites of the United States and Soviet Union. The tech is actually fairly low for cyberpunk, few implants or such. Computers are ubiquetious for the rich.