Limestone Block

The main difference between limestone and marble is that limestone is a sedimentary rock, typically composed of calcium carbonate fossils, and marble is a metamorphic rock. Marble forms when sedimentary limestone is heated and compressed by natural rock-forming processes so that the grains recrystallize.

Limestone is a bit more porous than marble, so it won't resist moisture as well. Limestone will need to be sealed more often than marble because it absorbs more and will therefore need more sealant than marble will. But that doesn't mean marble doesn't stain easily. You will need to seal marble too.