Answer:
A prime number is a number that's only factors are one and itself.
Explanation:
For example, the number 17. There are no 2 numbers other than 1 and 17 that can be multiplied together to get 17. However, the number 4 has many factors: 1,4 and 2,2. Because there are more factors then just 4 and 1, this number is not prime; it is composite.