The Apostrophe is a diacritic mark in punctuation‏‎.

It is used in 2 different ways in English‏‎:

to show possessive nouns
to show omitted letters

Generally we add an apostrophe s to the end of a noun to make it possessive:
the girl’s bike
Maggie’s farm
If there is a plural noun‎ which ends in an -s, then we add the…