History is the study of the human past as it is described in the written documents left by human beings. The past, with all its decisions completed, its participants dead and its history told, is what the general public perceives as the immutable bedrock on which we historians and archaeologists stand. History records start from the prehistoric age to the present time. 

Prehistory is the period of human activity between the use of the first stone tools c. 3.3 million years ago and the invention of writing systems, the earliest of which appeared c. 5,300 years ago. It was a period when a culture was written about by others, but writing had not yet been developed. Because there aren't any written records from human prehistory, so dating of prehistoric materials is crucial. Clear techniques for dating were not well-developed until the 19th century. Explore the age of the dinosaurs, learn about the Ice Age, find out about the early humans.

Ancient history is the aggregate of past events from the beginning of recorded human history and extending as far as the Early Middle Ages or the Postclassical Era. The span of recorded history is roughly 5,000 years, beginning with Sumerian Cuneiform script, the oldest discovered form of coherent writing from the protoliterate period around the 30th century BC. There were many civilizations such as the Egyptians, Romans, Greeks & Britains.  

In the history of Europe, the Middle Ages or Medieval Period lasted from the 5th to the 15th century. It began with the fall of the Western Roman Empire and merged into the Renaissance and the Age of Discovery. The Middle Ages is the middle period of the three traditional divisions of Western history: classical antiquity, the medieval period, and the modern period. The medieval period is itself subdivided into the Early, High, and Late Middle Ages. 

The Renaissance was a period in European history, from the 14th to the 17th century, regarded as the cultural bridge between the Middle Ages and modern history. It started as a cultural movement in Italy in the Medieval period and later spread to the rest of Europe, marking the beginning of the Modern age. 

Indigenous Australians are the Aboriginal and Torres Strait Islander people of Australia, descended from groups that existed in Australia and surrounding islands prior to British colonisation. The earliest definitely human remains found in Australia are those of Mungo Man LM3 and Mungo Lady, which have been dated to around 50,000 years BP. Luminescence dating has suggested habitation in Arnhem Land as far back as 60,000 years BP. Genetic research has inferred a date of habitation as early as 80,000 years BP. Other estimates have ranged up to 100,000 years and 125,000 years ago. 

The 20th century involve so many events that changed the world forever such as: World War I and World War II, nuclear power and space exploration, nationalism and decolonization, the Cold War and post-Cold War conflicts; intergovernmental organizations and cultural homogenization through developments in emerging transportation and communications technology; poverty reduction and world population growth, awareness of environmental degradation, ecological extinction; and the birth of the Digital Revolution. It saw great advances in communication and medical technology that by the late 1980s allowed for near-instantaneous worldwide computer communication and genetic modification of life. A lot has happened during that century.

The 21st century is the current century of the Anno Domini era, in accordance with the Gregorian calendar. It began on January 1, 2000 and will end on December 31, 2100. It is the first century of the 3rd millennium.