Inequality: A mathematical relationship where two values, expressions, or quantities are not equal, such as represented by the symbols '≠', '<', '>', '≤', or '≥'.
Equivalence: A mathematical relationship where two values, expressions, or quantities are equal or have the same properties, often represented by the symbol '='.
Real Numbers:The set of all numbers that can be represented on the number line, including positive and negative integers, fractions, and irrational numbers.