Modulo

Modulo is a mathematical operation that returns the remainder of a division between two numbers. It is represented by the percent symbol (%). For example, 10 % 3 would return 1, because 10 divided by 3 is 3 with a remainder of 1.

In programming, the modulo operation is often used to determine if a number is even or odd, or to cycle through a sequence of numbers. It is also useful for tasks such as calculating leap years, finding repeating patterns, and creating hash functions.

Here's a simple example of using modulo in JavaScript to check if a number is even:

```javascript let number = 12; if (number % 2 === 0) { console.log("The number is even"); } else { console.log("The number is odd"); } ```

Modulo can also be used in more complex mathematical operations and algorithms, making it a versatile tool in the field of mathematics and computer science.