Fluid and crystallized intelligence

Fluid intelligence and crystallized intelligence are two different types of intelligence.

Fluid intelligence is the ability to quickly solve problems you have never seen before. It's like when you've never seen a puzzle before, but you are able to figure it out.

Crystallized intelligence is the knowledge you gain over time. It's like studying a subject over a long period of time and learning the information. It's what you use when you take tests or finish homework assignments.