GC (Gas Chromatography) columns are specialized tubes used in gas chromatography systems to separate volatile compounds in a gaseous sample. These columns are typically made of a metal or fused silica and are packed with a stationary phase material that interacts with the components of the sample. As the sample is carried through the column by an inert gas, different compounds are separated based on their volatility and interaction with the stationary phase. GC columns are essential in fields like environmental analysis, forensics, and food quality testing.