Helicopters don’t need anything, they’re machines. The pilot may, however, decide that it’s preferable to land on a helipad when there is one available, typically to avoid raising dust or snow or grass, or because a helipad is certified to be flat, or because it’s safer.
The pilot have to identify from an angle from the top. When there is a circle with H, it is a helipad. Just the Air Traffic Control should give some supportive info about it. But, during storm, that support might not work. Then landing is on full assumption.
Specially the civil helicopters are not designed in a way so that at the last moment suddenly the decision from a landing can be changed to suddenly fly away like a bird ! Simply it will face an accident.
A helipad is platform for a rotary wing to land. It can be over land, over a building, on a floating ship also. But when you talk of an airport, it is the whole area on ground which consists of a runway for fixed/rotary winged aircrafts to land, a terminal to board, full complement of Navigational AIDS and equipment etc. A proper analogy in your question could be helipad vs runway or a heliport vs airport.