Base,Supplementary & special units

 Base Units:

• Base units are the fundamental units of measurement for physical quantities and form the basis for all other units.
• Examples of base units include meters for length, kilograms for mass, and seconds for time.
• Base units are agreed upon internationally and form the foundation for the International System of Units (SI).
  

Supplementary Units:

• Supplementary units are units derived from base units and used to express other physical quantities.
• Examples of supplementary units include meters per second for speed and newtons for force.
• These units are expressed in terms of base units and are used to describe physical quantities that cannot be expressed using base units alone.

Special Units:

• Special units are units used to express specific physical quantities that are not easily expressed using base or supplementary units.
• Examples of special units include lumens for luminous intensity, lux for illuminance, and decibels for sound pressure level.
• These units are used in specific applications and may have different definitions and relationships with other units for different physical quantities.
• Special units are used to express physical quantities with greater precision and accuracy than can be achieved using base or supplementary units alone.