Definitions for 101ˈwʌn oʊˈwʌn
Random House Webster's College Dictionary
comprising the introductory material in or as if in a course of study (used postpositively):
Economics 101; Life 101; It's Jungle 101 on a trip up the Amazon.
Origin of 101:
hundred and one, one hundred one, 101, ci(adj)
being one more than one hundred