Question

dont answer from internet​

Answer 1

The International System of Units (SI) provides definitions of units of measurement that are widely accepted in science and technology and which set measurement standards agreed to through the Convention of the Meter, a diplomatic treaty between fifty-four nations.

Answer 2

Answer:

before system international

every country have its own rule and unit for measuring of physical quantity

just like some country follow CGS(centimetre-gram-second) system ...it we talk about britain they follow FPS(Foot-pound-second) system

so when any research is published then scientists face difficultly in units because if a scientists belong to britain then they measure quantify in FPS unit but his/her research cant be understood by scientists who follow CGS unit

so there is a need of Common system of unit which was known as

systemae de Internationale

or International unit of sytem or SI unit of system

i hope u understand