The square root notation, represented by the symbol √, is called a "radical." The number or any variable inside the radical is referred to as a "radicand." Square roots are classified into two types: perfect and imperfect. The former results in an integer value, while the latter results in a decimal value.

In the mathematical expression √16, the radicand is 16. The number 16 is also a perfect square, which means that its square root is a whole number. When using the radical symbol, the square root of any number is always a positive value.