What is the difference between concrete and cement?

Cement is binding material and concrete is mixer of aggregate,sand and cement 

Concrete is a mixture of sand, gravel or crushed stones, water and cement.Cement is a binder, a substance used for construction that sets, hardens and adheres to other materials, binding them together.

cement is a binding material, while concrete is a mixture of cement aggregate sand & water.

Cement is one of the concrete ingredient.