The square root of a number is the value that multiplied by itself gives the original number. For example: √25 = 5, because 5 × 5 = 25.

The cube root of a number is the value that raised to the power of 3 gives the original number. For example: ³√27 = 3, because 3 × 3 × 3 = 27.

The square root of a negative number is not a real number. It's an imaginary number. For example: √(-4) = 2i. However, the cube root of negative numbers is real: ³√(-8) = -2.