Mountains resulting from sideways pressure on the crust are called folded mountains.

Here's a breakdown:

* Sideways Pressure: This pressure, also called compression, comes from the movement of tectonic plates. When two plates collide, the immense force pushes the rock layers upwards and folds them like a rug.

* Folding: The rock layers buckle and bend into wave-like structures. This is why folded mountains often have a characteristic ridged and valley landscape.

Examples of folded mountains include:

* The Himalayas

* The Alps

* The Andes Mountains

* The Appalachian Mountains

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