Prime: Prime numbers have exactly 2 factors; 1 & itself
Composite: Composite numbers have more than 2 factors.
Zero and One are NEITHER prime NOR composite!!
3
1 X 3
The only factors of 3 are 1 & 3 so 3 is a prime number.
10
1 X 10
2 X 5
The factors are 5 are 1, 2, 5 & 10. There are more than 2 factors, so 10 is a composite number.