How does anticlines and synclines and monoclines form bedrocks bend?

Anticlines form when rock layers are pushed upwards in an arch shape, while synclines form when rock layers are pushed downwards into a U shape. Monoclines form when one side of the rock layer is tilted and the other side remains horizontal. These bending of bedrocks are typically the result of tectonic forces, such as compression or extension, acting on the Earth's crust over long periods of time.