Mountains are made by nature. They are one type of landform. Mountains are tall and rocky. They have high elevation. Mountains rise high above the land around them. A mountain's height is measured by its relation to sea level. Sea level has zero elevation. A mountain's elevation means the distance above or below sea level. The tallest part of a mountain is called the peak. Mountains often have pointed tops. They often have steep sides. Mountains are taller than hills. Mountains don't all look the same. They are different because they formed in different ways.
The Earth's surface or crust is made of huge pieces called plates. They fit together like a jigsaw puzzle. The heat inside the Earth causes the plates to move. The Appalachian Mountains are folded mountains. They were formed when two plates pushed directly against each other.
Imagine a soft rug lying on the floor. One side is against a wall. What would happen if you pushed against the other side of the rug? The rug would be squeezed between the wall and your foot. It would fold, forming a series of ripples. The Appalachian Mountains were formed in much the same way. Instead of your foot and the wall, the rock layers of the land were squeezed by forces inside the Earth. The land between the two opposite forces was squeezed into folds like the rug.