How can you give an account the difference between a wet stain and an oil-based stain? Is there a track to remove either of them?

Is there a track to remove either of them?
Answers:    A wet stain will look dry
A greasy-oily stain will look wet

Dawn dish fluid will remove the oil-based stains
Oxiclean laundry stain remover spray is good for most stains.