History is the study of the past. People know what has happened in the past by looking at thingsfrom the past: books, newspapers and letters. Libraries, archives or museums collect and keep these things for studying history. A person who studies history is called a historian. A person who study prehistory is called an archaeologist and they study artefacts like pottery and stone tools instead of written sources.
People can learn about the past by talking to people who remember things that happened in the past. This is called oral history. When people who had been slaves and American Civil Warsurvivors got old, some historians recorded everything that they said, so that history would not be lost.
In old times people in different parts of the world kept different histories because they did not meet each other very often. Some groups of people never met each other. MedievalEurope, Ancient Rome and Ancient China all thought that they ruled the only important parts of the world and that other parts were "barbarian".
Renaissance - 15th century renewal of science etc., based on texts from Ancient Greece and Roman Empire that were preserved by Muslims and captured by Christians