Q: How is it you can get people who are very defined muscle wise and strong yet they have very slim physiques ? ie a high power to weight ration. Most people would say you would need to have big muscles to be very strong. This is important because most people do have the time, energy, dedication or genes to be bodybuilders.

A: There is no one answer I can give you, but it is a combination of factors:

• Different people can have vastly different genetic potentials for strength, power, and muscle mass. While everyone can make incredible progress from their untrained level, some people can become far stronger and/or more muscular than others even with the same level of training. That's just the way we are born. The same genetic potential allows some people to make tremendous progress from the kinds of routines that would be overtraining for others.
• Many people who seem to be born with slim yet powerful physiques have actually put in many hard years of training and eating right in order to achieve them.
• You do not need to become huge and muscular to be strong. While it's of course true that muscular people are strong, it's not necessary to be big to be strong. One can train specifically for strength and power as opposed to training for muscle mass. A good example of that are lightweight and lighter olympic weightlifters who can be far stronger in olympic lifts than much much larger bodybuilders. I have some strength-specific routines on my site, including this.
• Finally, a dirty little secret is that many millions of people use anabolic steroids to both maintain low body fat and/or build muscle mass. Anabolic steroids can greatly increase strength and muscle mass levels and decrease body fat levels. The downside of course, is that they are highly dangerous, can be psychologically addicitive, and illegal.

For all these reasons you should not compare yourself to other people, either physique-wise or strength-wise. Only be concerned about making progress in your own training.