What is the use of join here plz say what's happening here

Question

class SpecialString:
def __init__(self, cont):

self.cont = cont

def __truediv__(self, other):
line = "=" * len(other.cont)
return "\n".join([self.cont, line, other.cont])

spam = SpecialString("spam")
hello = SpecialString("Hello world!")
print(spam / hello)

Answer 1

join is used here to add a newline between self.cont, line and other.cont

Answer 2

how?

Answer 3

but that could have been done by \n

Answer 4

but that could have been done by \n