A scalar quantity is a quantitythat is invariable with respect to any system of coordinates, i.e. it never changes because of a transformation of coordinates. In comparison to vector quantities, a scalar is remarkable because it has only a magnitude, but no direction. A vector quantity is a quantity that is characterized both by a magnitude and a direction, and its coordinates change, obeying certain rules, if a transformation of coordinates takes place. In a broader framework of tensors, a scalar is a tensor of 0-th order (and has just 1 coordinate), whereas a vector is a tensor of 1-st order (and has 3 coordinates). The next would be a tensor of 2-nd order, which is essentially a matrix 0f 3x3 with 9 values.