Hey there! An expression doesn't have a left side, right side, or even an equals sign. It could just be something like "2+3" that you would just need to simplify. However, An equation sets two expressions/terms equal to each other, has a right and left side, and has an equal sign. Finally, an inequality " a relation that holds between two values when they are different." They use greater than, less than, greater than or equal to, or less than or equal to signs.