An equation is a statement that two quantities are equal. An inequality is a statement comparing two quantities that may or may not be equal. As we can compare one real number to another, we can compare a real number and a variable. This may seem a little like comparing apples and oranges, but is it really hard to compare apples and oranges? Apples are redder, oranges have more stuff to peel off. There—done.
We can represent inequalities using words, symbols, or pictures on a number line.