New things happen every day, something historic oftens goes down. Things such as:
New inventions (Ex: The first touch-screen phone)
New records (Tallest building)
New presidents and prime ministers (US election of Donald J Trump, 2016) The results of the winter Olympic games (This February.)
Almost anything that happens is a historical record of everything else. Interpretations may change on evidence found or other discoveries, example: the theory of plant cells has changed as more and more people discover more and more complex things, or how the list of suspects changes throughout an investigation.
I hope I helped, feel free to ask for more.