A crossroad (no 's') is a road which crosses another road.
A crossroads (usually with an 's') is a type of intersection. 'Crossroads' suggests a fairly simple form of intersection: it could simply be where two roads cross each other. It's often used figuratively, e.g, coming to a crossroads in life.
'Intersection' is a more general term and also covers other types of road junctions e.g. T-junctions or more complex configurations where multiple roadways meet. These may include traffic circles (US English) or roundabouts (British English).
I hope that helps.