How dogs Learn
The main difference between how we learn and how dogs learn is that dogs don't understand things "conceptually". They can't read something and understand how it works in "theory". They must do, or experience it in real life in order to learn it. This means that we cannot say our dog "knows" something until they can prove to us that they know it through their actions.
In most cases the first time a dog has a new experience their initial response to it is instinctual. That behavior came "pre-programmed" into the dog at birth. They will then adjust their behavior based on the consequence of that behavior, trying many things until they discover what works to either get what they want or to make something they don't like go away.
Dogs are really good at recognizing patterns and forming associations between things. Over a series of repetitions they can learn quite easily that A is always followed by B. Assuming the pattern is consistent, the dog's response will most likely be consistent. Over time, routine recognition and performance of patterns are what create our dogs habits. If our dog's habits are disagreeable to us, the first step in changing them is to change the patterns that created them in the first place.
When the dog discovers that their action has a favorable consequence, a memory is formed that increases their desire to repeat that action. When the dog discovers that their action has an unfavorable consequence, a memory is formed that decreases their desire to repeat that action.
From our perspective, we can view the dog's learning process using this simple pattern:
Signal > Response > Consequence
Some "thingy" (a command, a smell, an object, anything perceivable by the dog can be a signal) causes the dog to act (response). The dog's action creates an outcome (consequence).
From the dog's perspective, we can view the dog's learning process using this simple pattern:
Action > Memory > Desire
I (the dog) did something. The consequence was (good/bad). I (want/don't want) to do that thing again.