An iceberg is a large mass of freshwater ice that has broken off from a glacier or ice shelf and floats in open water. Icebergs are primarily found in polar regions, where they can vary in size from small chunks to massive structures that can tower above the ocean surface. The majority of an iceberg's mass is submerged underwater, making them difficult to spot from a distance. Icebergs are formed through a process called calving, where pieces of ice break away from glaciers due to melting or structural instability. They can pose significant hazards to ships, as famously demonstrated by the sinking of the RMS Titanic in 1912. Understanding icebergs is crucial for navigation and climate studies.