A unary operator operates on a single operand while a binary operator operates on a two operands.
For instance, a unary minus simply makes the operand negative. For example, if your operand is 5, a unary minus will make it -5. A binary minus operates on two different operands, subtracting one from another. So if the two operands are 5 and 3, applying a binary minus will result in 5-3 = 2.