The TNM system is a standardized method used by medical professionals to describe the extent of cancer in a patient's body. It stands for Tumor, Node, and Metastasis. The "T" indicates the size and extent of the primary tumor, the "N" refers to whether cancer has spread to nearby lymph nodes, and the "M" shows whether there are distant metastases, or spread to other parts of the body. This system helps doctors determine the stage of cancer, which is crucial for planning treatment and predicting outcomes. By categorizing the cancer's characteristics, the TNM system provides a clear framework for communication among healthcare providers and aids in research and clinical trials.