A mental model is a sort of thinking process applied to the real world, which is usually simple yet powerful to solve complex problems. In short, mental models are simple and yet effective solutions or guiding principles to complex real-life scenarios. Therefore, the central point is those complex problems can be solved with simple solutions that, in most cases, work much better than more complex solutions.
Heuristics

Bounded Rationality

Second-Order Thinking

Lateral Thinking

Moonshot Thinking

Biases

Dunning-Kruger Effect

Occam’s Razor

Mandela Effect

Crowding-Out Effect

Bandwagon Effect

Straw Man Fallacy

Gambler’s Fallacy

Base Rate Fallacy

Pygmalion Effect

Barnum Effect

Bottom-Dollar Effect

Bye-Now Effect

Butterfly Effect

IKEA Effect

Halo Effect

Ringelmann Effect

Law of Unintended Consequences

House Money

Snowball Effect

Hawthorne Effect

Read Next: Biases, Bounded Rationality, Mandela Effect, Dunning-Kruger
Read Also: Heuristics, Biases, Business Strategy, Business Models.