Cast Iron and cast steel   are two types of Iron carbon alloy.  The main difference between these two types of carbon are the carbon content and the composition characteristics. While Cast Iron is rich in carbon more than cast steel. Cast Iron contains over two percent of carbon and cast steel is less than 2% in weight. the purpose of this casting with carbon is to alter the property of iron for more arcane applications because iron itself alone is a soft metal and it is not ideal for construction materials. There is not much difference in the chemical composition between these two alloys but their physical properties differ significantly.

Both of these types are equally important alloys in the world of metallurgy in different ways.

Difference:

Steel is costlier vs cast iron is cheaper

Cast Iron has low melting point vs Steel has high melting point

Cast Iron can have any amount of carbon vs steel is made with a controlled amount of carbon.

Cast iron is brittle, more damping and absorbs vibration and noises vs steel is mild, harder to cast and has a relative high viscosity.

Cast Iron breaks on bending/denting vs steel does not break on bending.

Cast Iron has more compressive strength vs steel is tensile.