What are natural numbers?

Natural numbers are the basic counting numbers: 1, 2, 3, 4, 5, ...

• Symbol: N
• Always positive, never include zero (in standard school definition), no fractions or decimals.
• Infinite no largest natural number.

Hierarchy: N ⊂ Whole (W) ⊂ Integers (Z) ⊂ Rational (Q) ⊂ Real (R)

Natural numbers are the positive counting numbers starting from 1, forming the foundation of all other number systems.