This paradigm originates from Tiago Forte, author of Building A Second Brain. This technique is a great way to start a new piece of work. The key principle is to never start with a blank page. Before starting gather current thoughts, notes, ideas or other sources in a new note. This allows you to converge your ideas into something new. It helps to guide your efforts and focus you on the material in the front of you.
It separates two activities in your brain. Two activities that the brain finds hard to do simultaneously. These activities are:
Selection is a divergent process whereas sequencing is a converging activity. This shows why it is hard for the brain to do this at the same time.