Signal = The subset of tasks that directly advance your top goals today — the 3–5 mission-critical items. Noise = Everything else: distractions, low-impact tasks, endless meeting notes, trivial errands.
Steve Jobs targeted an 80% signal / 20% noise ratio daily — focusing on only 3–5 key priorities per 18‑hour period.
Elon Musk, in contrast, pushes toward 100% signal — cutting out all non-essential noise.