A "remainder" is what is left over after dividing one number by another. For example, if you divide 10 by 3, you get 3 as the quotient and 1 as the remainder. This means that 3 fits into 10 three times, and there is 1 left over. Remainders are important in math, especially in division problems where the numbers don't divide evenly. Remainders can also be seen in real-life situations, like when sharing candies. If you have 10 candies and want to share them among 3 friends, each friend gets 3 candies, and you will have 1 candy left. Understanding remainders helps in solving problems and making fair distributions.