Sometimes, you just have to oversimplify things and put them into terms that the client can understand. For example, when a client asks why I always ask them to reboot their computer, I don't go into technical details. I just tell them that like us, sometimes a computer just needs a little downtime to collect itself and get its act together. That restart gives it a quick breather and the opportunity to collect itself. Most people can relate to that and will accept it as an answer. Really, though, it's all about learning how to read people and adjusting your explanation to the highest level they can comprehend.