One of the major challenges for the presenter is making the message instantly clear. Audiences cannot click “back” or "rewind" and hear again what you just said. The audience member cannot say, "Hold on while I look up the meaning of that word," or "Give me a few minutes to get some background information online.” Your language choice must be instantly clear.
The most effective way to combat this challenge of immediate clarity is to use a comparison where you connect the familiar with the unfamiliar. I'm reading a book about World War II, Unbroken, by Laura Hillenbrand. In the book she discusses how difficult it was for a pilot to fly a B-24 bomber because of the way it was constructed and the bulkiness of fuel tanks needed in order to fly l6 hours without landing. To give the reader a clear understanding of how difficult this was and why pilots disliked flying this plane, she quoted one pilot who said, "It was like sitting on the front porch and flying the house!" You may never have been in a bomber or have any inkling about flying planes of that generation, but with this one sentence you understood how awkward and challenging this plane was to pilot.
The comparison can sometimes be a piece of humor as well as making a point clear. For example, you may not know much about defense configurations in basketball, but consider this comparison by one of the most successful NBA coaches, Norm Sloan. In talking about a zone defense he said, "It hate it. It looks like a stickup at 7-Eleven. Five guys standing there with their hands in the air."
Such comparisons can make a world of difference in audience interest in what you have to say.