An object experiences acceleration only when forces act upon it, and in the absence of forces, it adheres to Newton's First Law. To identify an inertial reference frame, one must recognize that it is a frame where an object either remains at rest or moves with constant velocity, indicating zero net force. Utilizing Newton's Second Law (F=ma), if an object has acceleration with no forces acting on it, the net force is zero, confirming it is in an inertial frame. Therefore, the reference frame where the object maintains constant velocity or is at rest is classified as inertial. This understanding is crucial for accurately describing motion and applying Newton's Laws of Motion.