I was going through the chapter of "Newton's Laws of Motion", where I was introduced to the concept of inertia in Newton's First Law. I saw that all objects that have mass will have inertia. But I do not really get it.
What is the reason behind objects having inertia? And why is it that only those objects that have mass have inertia? I tried researching on the matter a bit, but until now I have not found any satisfactory answer.