One popular way to explain this is Howard Gardner’s Multiple Intelligences theory. It says intelligence is not only “book intelligence” or IQ. People can be intelligent in different ways.

1. Linguistic intelligence

Skill with language, words, reading, writing, speaking, storytelling.

Examples: writers, speakers, lawyers, poets, teachers.

2. Logical-mathematical intelligence

Skill with numbers, logic, patterns, problem-solving, analysis.

Examples: mathematicians, programmers, scientists, accountants, engineers.

3. Spatial intelligence

Skill with visualizing space, shapes, directions, maps, design, and how things fit together.

Examples: architects, designers, pilots, drivers, artists, people good with directions.

4. Bodily-kinesthetic intelligence

Skill with body movement, hands, tools, coordination, physical precision.

Examples: athletes, dancers, surgeons, carpenters, mechanics, electricians.

5. Musical intelligence

Skill with rhythm, melody, sound, pitch, singing, instruments, music patterns.

Examples: singers, composers, musicians, music producers.

6. Interpersonal intelligence

Skill with understanding other people, reading emotions, communicating, leading, persuading.

Examples: managers, salespeople, therapists, politicians, teachers.

7. Intrapersonal intelligence

Skill with understanding oneself—one’s emotions, strengths, weaknesses, motivations, and values.

Examples: philosophers, writers, spiritual thinkers, good decision-makers.

8. Naturalistic intelligence

Skill with understanding nature, animals, plants, weather, environment, and living systems.

Examples: farmers, gardeners, biologists, veterinarians, environmentalists.

9. Existential intelligence

Skill with deep questions about life, death, meaning, God, morality, and purpose.

Examples: philosophers, religious thinkers, spiritual teachers, serious writers.

A simple way to remember:

Some people are word-smart, some are number-smart, some are body-smart, some are people-smart, some are self-smart, some are music-smart, some are nature-smart, and some are direction/design-smart.

So a person who is not strong in school may still be highly intelligent in practical work, business, sports, music, people handling, or navigation.