Second Brain

A "second brain" is a metaphor used to describe a system of organizing and storing information that can be used to offload and externalize some of the cognitive load associated with memory and decision-making. The idea is that by creating a separate, reliable, and easily accessible system for storing information, you can free up mental space and reduce the need to rely on your own memory.

It can be implemented in a number of ways, such as using a physical notebook, a digital note-taking app, or a combination of both. The key is to have a system in place that allows you to easily capture and organize information, so you can access it later when you need it. This can include notes, ideas, tasks, research, reference materials, etc.

The second brain concept is often associated with the Zettelkasten.

Popularised by Tiago Forte in his book How to Build a Second Brain