A binary operator is:

• + - * / \\ % for arithmetic operator
• | & ^ << >> for bit operator
• && || == != for boolean operator

Each operator have a priority. For example, + has less priority than * because we apply * before we apply + (2 + 4 * 2 = 10 because we start by doing ‘4 * 2’)

Binary operator expression needs a left expression, a binary operator and will compute a right expression to put at the right place in the tree to be sure the priority of the operation is preserved.