Question

what is eucluid division lemma​

Answer 1

check , it is in textbook
for two integers a & b there exist unique integers satisfying
a=bq+r,where 0<_r<_b

Answer 2

Euclidean division is the process of division of two integers, which produces a quotient and a remainder smaller than the divisor. Its main property is that the quotient and remainder exist and are unique, under some conditions.