History is always a study of change. Not everything changes. Some remains same and others change. Things that remains same for many years are something like that we always need food, we always need shelter, fern plant still exists, sun still exists, the Earth didn't break as yet in to several pieces, the Moon did not break and split.
There are other things that change like the clothes we wear, the vehicles we travel, extinct dinosaurs, the ice age that is not existing anymore, the world that has split into several countries, the oceans that keep growing and changing etc.