Definitions of important key concepts
Key concepts, mental models, and frameworks for knowledge workers who want to think clearly, work intentionally, and learn effectively. Each entry gives you a clear definition, practical context, and links to related ideas.
A
Active Recall
Retrieve information from memory instead of passively reviewing it.
Atomic Notes
Self-contained notes that capture one idea each and connect into a knowledge network.
C
Cognitive Load
The total mental effort your working memory is handling at any given moment.
Context Switching
The hidden cost of shifting your attention between tasks.
D
Deep Work
Focused, distraction-free work on cognitively demanding tasks.
F
Flow State
A state of complete absorption where focus, creativity, and performance peak.
G
Getting Things Done (GTD)
A method for capturing, clarifying, and organizing everything that demands your attention.
J
Journaling
The practice of writing down thoughts and reflections to support clearer thinking.
M
Metacognition
The ability to observe and reflect on your own thinking.
Mindful Productivity
Matching your effort to your energy and context instead of maximizing output.
O
Opportunity Cost
The value of what you give up when you choose one option over another.
P
Parkinson’s Law
Work expands to fill the time available for its completion.
Personal Knowledge Management (PKM)
A structured approach to capturing, organizing, and connecting information over time.
Progressive Summarization
A layered note-taking technique that makes your notes more useful every time you return to them.
S
Second Brain
A digital system for storing and connecting knowledge outside your biological memory.
Shallow Work
Routine, low-concentration tasks that rarely produce new value.
Spaced Repetition
Reviewing information at increasing intervals to beat forgetting.
Sunk Cost Fallacy
The tendency to keep going because of what you already invested, not what lies ahead.
T
Time Blocking
Assigning specific tasks to defined blocks of time in your calendar.
Toxic Productivity
When the drive to be productive becomes compulsive.
Z
Zeigarnik Effect
The tendency of your brain to hold on to unfinished tasks until they are resolved or captured.