This question is about how big hills called mountains are made on Earth and what natural forces change the land to make these high areas. Geographical or scientific approach with reference to this answer is welcomed.
Mountains are formed because the Earth’s surface is made of large pieces called plates that move slowly. When two plates press together, the ground gets pushed up and mountains appear. In some places, the Earth’s crust cracks and rises, creating mountains too. Volcanoes can also form mountains when melted rock comes out and cools. So, mountains are created when the Earth’s crust moves and lifts over many years.