It's a number that can evenly be divided by numbers other than 1 or itself. Example: 8. You can multiply the factors 2 and 4 and get 8 other than multiplying 8 and 1.
A whole number that can be divided evenly by numbers other than 1 or itself. Example: 9 can be divided evenly by 3 (as well as 1 and 9), so 9 is a composite number. But 7 cannot be divided evenly (except by 1 and 7), so is NOT a composite number (it is a prime number).
