The "Order of Operations" is a set of rules that determines the sequence in which mathematical operations should be performed to ensure accurate results. The common acronym used to remember this order is PEMDAS, which stands for Parentheses, Exponents, Multiplication and Division (from left to right), and Addition and Subtraction (from left to right). Following the Order of Operations is essential when solving complex equations. For example, in the expression 3 + 5 × (2^2 - 1), you would first calculate the value inside the parentheses, then the exponent, followed by multiplication, and finally addition to arrive at the correct answer.