GC, or gas chromatography, is a laboratory technique used to separate and analyze compounds in a mixture. It works by vaporizing the sample and passing it through a column filled with a stationary phase. Different components of the mixture travel at different speeds, allowing them to be separated and identified as they exit the column. This method is widely used in various fields, including environmental testing, food safety, and forensic science. By providing detailed information about the composition of a sample, GC helps scientists and researchers understand complex mixtures and ensure safety and compliance with regulations.