Absolute values represent the distance of a number from zero on the number line, disregarding its sign. The absolute value of a number is always non-negative, meaning it can be zero or positive but never negative. Key properties include that the absolute value of a positive number is the number itself, while the absolute value of a negative number is its positive counterpart. Additionally, the absolute value of zero is zero. Understanding these properties is fundamental in mathematics and helps in solving various equations and inequalities.