The pitch deck is a presentation that entrepreneurs put together when seeking a round of financing from investors. On average pitch decks have no more than 19 slides.
As described in my book, The Art of Startup Fundraising, ultimately founders need two different sets of pitch decks. One version will be with a lot of text and information which will be shared with people via email. The other version will be the pitch deck that entrepreneurs present to investors in person with more visuals. Having more visuals will contribute to having investors focused on you.