Service Entrance cable which picks up where the utility service drop leaves off. Typically, it connects at the top of the service mast with utility rated bug nuts and runs down to the meter base. From the meter, it is usually used to enter the building and connect to the distribution panel. Sometimes you may see it used on branch circuits as permitted by the National Electrical Code.
"They can rope an entire house in one day."
Type NM cable, 14 AWG or 12 AWG. Because it's only used in residential occupancies. Looks like rope and is slung around line one.