Short answers, pulled from the story.
European powers controlled only ten percent of the African continent in 1870. Most territories lay along the coastlines where mortality rates from tropical diseases like malaria kept inland regions uninhabitable for outsiders.
Otto von Bismarck convened the 1884, 1885 Berlin Conference to discuss the African problem among European powers. Diplomats laid down rules of competition by which great powers were guided in seeking colonies and agreed that no territory could be formally claimed before being effectively occupied.
Germany became the third-largest colonial power in Africa with 2.6 million square kilometers of territory and 14 million subjects by 1914. Its possessions included Southwest Africa, Togoland, the Cameroons, and Tanganyika.
Britain sought control of areas on the southern and eastern coasts of Africa for stopover ports on the route to Asia and its empire in India. The Suez Canal completed in 1869 became a key waterway requiring protection through military bases and coaling stations.
Between 1904 and 1908 Germany committed genocide against the Herero people resulting in up to 65,000 deaths representing eighty percent of their total population. Ten thousand Nama people died during this period representing half their total population through starvation thirst or forced labor camps like Shark Island.