Deep Work
In his book Deep Work, Cal Newport describes deep work as:
Professional activities performed in a state of distraction-free concentration that push your cognitive capabilities to their limit. These efforts create new value, improve your skill, and are hard to replicate.
Alternatively, shallow work as:
Non-cognitively demanding, logistical-style tasks, often performed while distracted. These efforts tend to not create new value in the world and are easy to replicate.