Natural gas reserves refer to the quantities of natural gas that are discovered and can be extracted economically. These reserves are typically found in underground rock formations and can be classified into three categories: proven, probable, and possible reserves. Proven reserves are those that can be extracted with a high degree of certainty, while probable and possible reserves have lower levels of certainty regarding their extraction. The measurement of natural gas reserves is crucial for energy planning and economic forecasting. Countries with significant natural gas reserves, such as Russia and the United States, play a vital role in the global energy market. These reserves are essential for meeting energy demands and can influence energy prices worldwide.