TITLE: About the Order of Groups
QUESTION [6 upvotes]: Is there any theorem that states the all the finite groups of order n are the same? or some sort of theorem that refers to the order of two finite groups?
If anyone can post a reference to this topic will be great...
10x in advance

REPLY [3 votes]: You might want to read the paper of Besche, Eick and O'Brien http://www.math.auckland.ac.nz/~obrien/research/2000.pdf which contains a table of the number of groups of order $n<2001$.