What does odd and even mean in math?

In mathematics, odd and even refer to the classification of integers based on their divisibility by 2. An even number is any integer that can be divided by 2 without a remainder, such as -4, 0, 2, or 6. In contrast, an odd number is an integer that, when divided by 2, leaves a remainder of 1, including numbers like -3, 1, 3, or 7. This distinction is fundamental in various mathematical concepts and operations.