Short answers, pulled from the story.
The Kingdom of Denmark consists of three constituent parts: metropolitan Denmark (the Jutland peninsula and 406 islands), the Faroe Islands, and Greenland. The Faroe Islands and Greenland are autonomous territories that govern their own domestic affairs but remain part of the Danish Realm under Copenhagen's authority over defence, foreign policy, and monetary policy.
Denmark peacefully became a constitutional monarchy on the 5th of June 1849, when a new constitution established a two-chamber parliament and ended the absolute monarchy that had been in place since Frederick III consolidated power after the siege of Copenhagen in 1660.
Denmark's flexicurity model combines high employer flexibility with strong worker security. Employers may hire and fire workers freely, while unemployment compensation between jobs is relatively high. Initial and long-term net replacement rates for unemployed persons were 65% of previous net income in 2016, above the OECD average of 53%.
Several widely used programming languages were created by Danish-born computer scientists: C++ by Bjarne Stroustrup, PHP by Rasmus Lerdorf, C# by Anders Hejlsberg (who also created Turbo Pascal and Delphi), Ruby on Rails by David Heinemeier Hansson, and the V8 JavaScript engine and Dart by Lars Bak.
Denmark operated trading outposts in West Africa, most notably Fort Christiansborg in Osu, Ghana. Through that outpost, approximately 1.5 million enslaved people were traded as part of the Atlantic slave trade.
The two Jelling runestones contain the first recorded use of the word Denmark within Denmark itself. One was erected by Gorm the Old, considered Denmark's first king, around 955, and the other by his son Harald Bluetooth around 965. The larger stone is popularly called the baptismal certificate of Denmark.