A square root is a mathematical operation that finds a number which, when multiplied by itself, gives the original number. In other words, it is the inverse operation of squaring a number. The symbol for square root is "√". The number being rooted is called the radicand. Every non-negative real number has a unique non-negative square root, called the principal square root or simply the square root. The principal square root is denoted by the symbol "√". For example, the principal square root of 9 is 3, which is written as "√9 = 3". Every positive number has two square roots, one positive and one negative. For example, both 2 and -2 are square roots of 4. The positive square root is usually referred to as the square root. Most square roots are irrational, meaning that their decimal form continues forever without a repeating pattern.