To share a deck with someone all you need to do is send them a link which is in the format
slides.com/<username>/<deckname>. This link can be found in the Share popup which is opened by pressing the Share symbol in the editor, on any deck page or on your profile page. The Share popup also includes options for embedding or emailing a deck to someone.
An example of what the deck page looks like:
Learn how to embed decks on other pages.