Why are SI units helpful?

Hint: All that you must know about the SI units, what it stands for? and about their uses. So here we are going to see what SI units are, what their uses are and why it is very helpful. Also the reason why it is preferred to the old English system of measurement.

Complete answer:
 SI units are used universally in technical and scientific research to avoid confusion with the units as it is a unit of an international system of measurements. It helps to understand the measurements in one set of unit systems in the entire world by having a standard unit system so the SI unit is very much important. It is used for defining\[22\] derived units which are made up of \[7\] base units. The term SI units can be expressed either as fractional quantities or as a standard multiply.
SI is preferred to the old English system of measurement reason are:
Rather, on precise and definite standards the SI units are not based on the arbitrary constant of the human body.
They are like our number that the SI unit uses base\[10\], so that’s why it is much easier to learn, remember and convert between units.
The prefixes used in SI are taken from Latin and Greek, and they refer to the numbers that the terms represent. The number of millimetres in a kilometre you can easily calculate. Like, how many inches in a mile?
 The derivation of one unit occurs from the other units without conversion factors. E.g. $1N$ (Newton) is the force needed to give $1kg$ (kilogram) of mass an acceleration of $1\dfrac{m}{{{s^2}}}$ Try that with the 'English' units so the SI units are interrelated in a such a way.
Its usage allows scientists from different regions to use a single standard in communicating scientific data without vocabulary confusion. so what SI unit is mostly used around the world.

Note:
Base units and derived units are the two classes of the SI units. The two supplementary units are one is radian and another is steradian, they are now subsumed into the class derived of SI units.