What is this and how do I get rid of it?

Someone's not wearing non-marking shoes. Quick google:

• Using Oil-based Sprays. Apply a spray such as WD-40 or cooking spray to the mark. ...
• Using Toothpaste. Toothpaste is one of the universal products on the market that can also be used to remove various stains from floors. ...
• Use A Tennis Ball. ...
• Try To Use a Pencil Eraser.