The first approach is a scale shifting exercise, which covers the entirety of the fretboard in the key you're in. The tab demonstrates this in the key of G but you should do this in all 12 keys to fully understand the concept.
The second exercise illustrates how to play scales without starting on the root note. This will give you a better understanding of the relationship between scales and keys because you'll be able to visually see where notes differ in different scales.
