What is the difference between a syncline and an anticline?

A syncline describes an area where different strata of rock have been folded (either symmetrically or asymmetrically) in a horseshoe/U shape, with the youngest formed rocks located within the centre, and the older rocks on the outside. An anticline is the opposite – it is an upside down horseshoe shape, with the oldest rocks on the inside and the youngest on the outside.