We talk about note-taking as if it were a single activity, but that’s not the case. There are at least three use cases for taking notes. You’ll become a more effective note-taker — and better thinker — if you know the difference between them.

The most obvious use case for taking notes is to remember things. The classic example is a shopping list: while you’re in your kitchen, you jot down things you’re missing so you’ll get them at the grocery store. Such notes are an extension of your memory.

A second use case for taking notes is to learn or understand something. When you highlight passages in a book and/or scribble in its margins, you’re picking out salient ideas to build a model in your mind. These notes are an aid to comprehension.

A third use case for taking notes is to explore an idea space. Think “mind dump”: you’re making ideas concrete by writing them down, sketching possible configurations, surfacing patterns, etc. These are notes in service to creativity.

While these use cases are related — i.e., you can better remember things you’ve understood or created — they’re not the same. We use the word “note” in all three cases, but they’ll likely take different forms. The resulting “notes” don’t look much like each other.

I use different apps for all three cases. For example, when I’m making a shopping list, I use Apple Notes. This app is ideal for this use case: since it’s on my phone, I can walk through the kitchen to see what we need. Apple Notes also can present items as a checklist.

But I don’t use Apple Notes when I’m learning from a book. Instead, I use a combination of the Kindle, Readwise, and Obsidian. I highlight and annotate on Kindle. Then, Readwise syncs those annotations to Obsidian, where I synthesize what I’m learning.

And when I’m exploring an idea space, I usually turn to Tinderbox if I’m dealing with a conceptual domain or pen and paper (or some other means of sketching) if it’s a more visual problem. Outliners can also be helpful for this purpose.

The point is that even though we call all these things “notes,” they’re different media suited for different needs. As with carpentry, gardening, and many other domains, a key to becoming a more effective thinker is learning which tools are best for which tasks.

No one tool will do everything you need, so experiment with various tools to see which help you think better. When you find one that works, you can go deeper. But always consider each tool part of a cognitive toolset, not a “magic bullet” that will meet all your use cases.