A control system is often designed to reduce the difference between the actual and desired output (error) by using the error signal itself to modify the input.
This is the principle of closed-loop feedback control. Engineers use it to design systems that control everything from the flight path of a cruise missile to the temperature of your living room.
Please read the two paragraphs above again, if you are unfamiliar with this stuff. They present the essential ideas in a few sentences, even if the description could be faulted.
(And if you are really good at this, please, help describe the ideas in simpler terms in the comments. Thank you.)
There are two important elements in a control system:
Sensors to measure the appropriate variables
Without sensors, it's like flying an aircraft without knowing your altitude, location, speed, the orientation of the craft, etc.
A model of what is being controlled
Without an appropriate model, it's like handing over the aircraft to your refrigerator thermostat, which doesn't understand (has no model appropriate for) aircrafts in flight. But more about it in a later post.
Now, much the same thing happens within our body, which has an enormously complex control system.
Do you slouch? Or know someone who does? How easy it is to be unaware of the slouch. Or the fact that we habitually lean to one side, or slide forward in the chair, or keep the shoulders pushed up while typing. And most importantly, we are seldom aware any of these postural defects.
We think that we are sitting straight in a comfortable, neutral pose and discount the information about the slouch that our senses send in. Over time, the sensory information gets degraded by repeatedly being modified (discounted) and we lose the calibration. We no longer have reliable information for efficient and effective control.
Yoga makes you aware of your body: How well is your weight distributed? How straight is your spinal column? That sort of thing. And this give the body an opportunity to recalibrate the sensors periodically.
You already know from the aircraft analogy, just how important accurate information is. I leave you think how its lack affects your body.