In mathematical
group theory, given a
prime number p, a
p-group is a group in which each element has a
power of
p as its
order. That is, for each element
g of a
p-group, there exists a
nonnegative integer n such that the product of
pn copies of
g, and not less, is equal to the
identity element. The orders of different elements may be different powers of
p. Such groups are also called
p-primary or simply
primary.