Apokolips was created by Jack Kirby and was part of Kirby's Fourth World.
Apokolips is a large planet that embodies the worst aspects of hell, and is ruled by The Embodiment of Evil, The Mega Emperor, The Supreme Ruler known as Darkseid. Occupied in another dimension of the reality, Apokolips is the counterpart to the idyllic New Genesis. This dimension can only be accessed via a Boom Tube enabling device (such as a Mother Box or a Lantern Power Ring zeroed in on the frequency). The face of the planet is comprised of a single industrial complex, dotted with roaring fire pits (constantly erupting molten fire and heat from the center). Every aspect of the planet is devoted to a war that can be waged on a universal level. Training, constructing, maintaining instruments of war, whether it be against the heroes of Earth or the inevitable war with New Genesis that will end this age of Gods. As such, Apokoliptian technology is considered the most dangerous in all the universe, and has been the cause of innumerable sufferings and miseries.
The general population is comprised of a broken, submissive peoples known as Lowlies. Many of these lowlies were captured from conquered or destroyed planets. The fighting force of Apokolips are the Parademons. These brutes are equipped with armor and weapons forged in the pits of Apokolips. These shock troops possess strength, invulnerability and an immunity to pain burned into them from the fires of Apokolips. The most feared fighting force of all the New Gods, are The Furies. The Female Furies are trained to be the personal guard of Darkseid. Lastly there are Darkseid's Elite, akin to a King's Court. These are Kanto (master assassin), Granny Goodness (Headmistress and leader of the Furies), Grayven & Kalibak (the sons of Darkseid), Devilance (expert hunter), Steppenwolf (Master General) and Desaad (Torture expert and counselor who manages the day to day operations of Apokolips)
In Kingdom Come, Darkseid's son, Orion, is shown to have inherited Darseid's mantle and to have become the ruler of Apokolips. What is shown of Apokolips in this story is quite similar to how it is typically depictied but It remains unclear if overall living conditions had improved for it's inhabitants under Orion's rule.
Apokoliptan technology is the most advanced in the entire DC universe. All gadgets are at the disposal of Apokolips's supreme monarch, Darkseid. Such gadgets include but are not limited to: energy weapons, boom tubes, mother boxes, force field technology, starships capable of instellar travel, and mass mind control devices. Apokoliptan technology is so advanced that Darkseid uses it to wreck havoc upon entire alien civilizations.