the action of introducing something

issues arising from the introduction of new technology

the introduction of muskrats into central Europe

a formal presentation of one person to another, in which each is told the other's name

he returned to his desk, leaving Michael to make the introductions

a letter of introduction

a thing preliminary to something else, especially an explanatory section at the beginning of a book, report, or speech

your talk will need an introduction which states clearly what you are talking about and why