The metric system, also known as the International System of Units (SI) or the decimal system, is a system of measurements that uses standard units to measure physical quantities such as length, mass, and time. Some common synonyms for the metric system include the SI system, the International Metric System, and the decimal metric system. The metric system is widely used throughout the world, except in the United States where the imperial system is still used. The benefits of the metric system include ease of conversion between units, consistency in measurement, and global standardization.