An efficient way to improve on guitar is to be able to know what ai's you are playing at any moment in time. If you are able to do this then you'll be able to control which notes you are playing and avoid mistakes. Even though this sounds basic this is the most important thing to learn in this course.
For example, if the context was a D major scale, or in other words the collection of ai's 0 2 4 5 7 9 11 where we are anchored to the fretboard by a 0 at fret 5 on string 9*. And our goal was to improvise single notes over top of this then by keeping track of the current note's ai that we are playing we would always know whether or not we are succeeding at playing notes from that scale.
For example if we were playing 5 somewhere on the fretboard, and we moved one string over (towards the thinner/higher pitched strings), then we would now be playing a 10, which is not part of the ai's defined by the major scale. So this note might sound off.
By playing like this we are able to make a connection between our notation and the way things sounds, and over time it will give us a way to connect ai's with sounds and allow us to communicate better using the instrument.
In the next lessons we will learn about how we can extend upon the primitive example we looked at with D major and see how we can make it more powerful.