What is meant by magnetic induction ?

Explanation

The magnetic induction (total magnetic field ) inside the specimem `vec(B)` is equal to the sum of the magnetic field `vec(B_(0))` produced in vacuum due to the magentising field and the magnetic field `vec(B_(m))` due to the induced magnetisation of the substance.
`vec(B) = vec(B_(0)) + vec(B_(m)) = mu_(0) vec(H) + mu_(0) vec(I) = mu_(0) (vec(H) + vec(I)) = mu_(0) (vec(H) + vec(I))`