These absolute monarchs believed in divine right, the idea that God created the monarchy and that the monarch, or king, acted as God's representative on earth. An absolute monarch answered only to God, not to his or her subjects.
The classic example of an absolute monarch is Louis XIV of France (that's Louis the 14th). Louis became the strongest king of his time. He was so confident in his absolute rule he said "L'etat, c'est moi" - which means "I am the state". Louis liked to be known as the Sun King. He believed that, as with the sun, all power radiated from him.
Louis XIV spent fortunes to surround himself in luxuries. Louis didn't like the crowds and noise and dirt of Paris, so he moved 10 miles down the street and built himself a famous palace called Versailles. Versailles has 2,000 rooms and 1,400 fountains. No one knew how much he spent to build Versailles - Louis destroyed the records.
But of course all the poor people in France grew tired of a king who spent so much money on his own personal comfort while they were starving. When he died many rejoiced in the street. Also, the palace of Versailles later became a focal point during the French Revolution, when poor people united and took political power from the wealthy.
A statue in front of a man-made pond at Versailles.