Learner's definition of INTRODUCTION
1 [count] : the act of making a person known to others by name — usually plural
Once we finished the introductions [=once everyone was introduced], the meeting began.
I'll make the introductions. [=I'll introduce everyone]
2 [noncount] : the act of introducing something: such as a : the act of bringing something into practice or use for the first time b : the act of making a product available for sale for the first time c : the act of presenting something for discussion or consideration
d : the act of bringing something (such as a plant or animal) to a place for the first time
the introduction of evidence at the trial
the introduction of a new topic for conversation
the introduction of the bill to Congress
She told the audience, by way of introduction, that the research was completed a year ago.
3 [count] : a statement made to an audience about someone who is about to speak, perform, etc., or something that is about to begin
◊ A person who needs no introduction is well-known to the audience.
4 a : the beginning part of a book, essay, speech, etc., that explains what will follow in the main part b : the beginning part of a piece of music 5 [count] : something (such as a book or a course of study) that provides basic information about a subject — + to 6 [singular] : a person's first experience with something — + to 7 [count] : something that is added or introduced to something else