What Is A Syncline & Anticline?

Geology & Geomorphology (landscapes & geologic processes) What is an anticline? What is a syncline? How do these geologic terms/formations form in nature? Connection with: Earth's interior processes Convection Currents Crustal deformation Plate tectonics Orogeny Supercontinents Convergent plate boundaries Stress, force and strain on rocks Ductile deformation