My career has put me in the position where I often am explaining complicated matters. It might be how a technology works, or how an ecosystem functions, or the behaviors of certain markets or segments of the populace, or any number of elusive topics. In these circumstances I have found that there's no surrogate for a metaphor or an analogy.
Let's take the example of when I was on the other end. Early in my career I was in charge of product management for a line of products that depended on sophisticated image recognition technology. We were soon to release a new image recognition engine, and the VP of core tech (whom I'll call M) and I had retreated to a conference room to figure out how we'd describe the new innovations in this engine.
M kept speaking in similes. "It's like a map of Florida," she would say and then elaborate on that analogy. Or "It's like a pointillist painting."
The conversation wasn't coming to resolution with the alacrity that I desired, so I rather impatiently said, "Why don't you stop telling me what it's like and just tell me what it is."
M looked at me for a moment and then turned and wrote a very long mathematical equation on the white board. It was utterly unintelligible to me, as one needed a Ph.D. in a specific field of mathematics even to understand how this technology worked. M said to me, "That's what it actually is. Now, let's get back to talking about what it's like."
And that's where the analogies come in. A responsible analogy can distill down the important aspects of a complex subject and make the salient points intelligible to large numbers of people who are missing the highly specific information, background, or education to make sense of the direct details. In my seven years at VeriSign I was dealing with issues of security and trust and therefore found myself frequently discussing locks and safes and automobile air bags. These familiar items provide an understood context and framework that we all can grab on to.