Can someone please give me a dummy's definition of a tensor? We always use the stress/strain tensor in my structures class and the inertia tensor in my dynamics class. The only thing I really see between the both of these is that they are symmetric 3x3 matrices, so whats so special about them that makes them tensors? Here's what I know A scalar is tensor of order 0, a vector has order 1, and a matrix has order 2 Also I think I remember seeing something about how tensors can always be transformed to a different frame but retain some property? This is consistent with all the transformations we do on these matrices. But, is the fact that they are symmetric matrices that can be transformed to different basis the reason why they are tensors?