Definitions of introduction:

• noun:   the act of beginning something new
• noun:   the first section of a communication
• noun:   a basic or elementary instructional text
• noun:   a new proposal

  Example: "They resisted the introduction of impractical alternatives"

• noun:   the act of putting one thing into another
• noun:   formally making a person known to another or to the public
• noun:   the act of starting something for the first time; introducing something new

  Example: "He regards the fork as a modern introduction"