An iceberg is a large mass of ice that has broken off from a glacier or an ice shelf and is floating in open water. The part of the iceberg that is visible above the surface of the water is called the "tip," while the majority of its bulk lies hidden beneath the surface, referred to as the "submerged" or "hidden" portion. This submerged portion is much larger than the portion that is visible, with about 90% of an iceberg's total mass being underwater. The term "iceberg" can also be used metaphorically to describe a situation where only a small part of a problem or issue is visible, while the majority remains hidden or unknown.