Is an example of a non--contact force

Newton's law of universal gravitation \[ F = G\> {{m \, m'}\over{r^2}} \, , \qquad G=6.67\times10^{-11} {\mbox{Nm$^2$}\over\mbox{kg$^2$}} \]

On Earth's surface, $m'=M_E$ and $r=R_E$ \[ F = m\, \left({{GM_E}\over{R_E^2}}\right) = mg = W = \mbox{weight} \]

Weight $\vec{W}$: a force, a vector, measured in N (or lb) vs. mass $m$: a scalar, measured in kg (or slug)