The Metric System is a set of measurements to measure the quantities of various things.
ex:-

• Length - Metre
• Mass - Kilogram
• Volume - Litres
• Quantity - Mole
• Temperature - Kelvin
• Electromagnetism - Amphere
• Time - Second
• Luminous Intensity - Candela

Derived units with special names

There are currently 22 units with special names in the metric system. These are defined in terms of the base units or other named units.

• Electrical potential - Volt
• Electrical resistance - Ohm
• Magnetic flux density - Tesla
• Magnetic flux - Weber
• Electrical capacitance - Farad
• Electrical inductance - Henry
• Electrical conductance - Siemens
• Electrical charge - Coulomb
• Mechanical or electrical power - Watt
• Mechanical force - Newton
• Electrical or thermodynamic energy - Joule
• Pressure - Pascal
• Radioactive decay - Becquerel
• Absorbed ionizing radiation - Sievert
• Ionizing radiation - Gray
• Luminous flux - Lux
• Luminous intensity - Lumen
• Circular arc - Radian
• Sherical surface area - Steradian
• Thermodynamic temperature - Degree Celcius
• Catalytic activity - Katal
• Cycles per second (inverse of second) - Hertz

For more informaion.