Hard floor stains whether it be hardwood, concrete or tile can be easier to remove if you mop them and then vacuum them. Long standing debris that has dried on a hard floor can also loosen to be vacuumed.
If the stains or debris is really stubborn let a small amount of diluted white vinegar penetrate them for 5 minutes. It’s not good to let water stand on any hard surface. Hardwoods especially will bow over time the more water is left standing on them. Hot water and vinegar is ideal for hardwoods because of the fast drying vinegar does.
If you ever have any questions about residential cleaning email me any time. My email address is firstname.lastname@example.org