What is the difference between physical dimensions and physical quantities?

What is the difference between physical dimensions and physical quantities if the dimension of mass is also mass?

There is a difference between the unit of work done and the torque acting on the body. The unit of work is Joules ($$J$$ or $$Nm$$), whereas that of torque is ($$Nm$$). Comparing dimension wise, they both have the same; but they are not the same physical quantity. Torque is the rotational analogue of force . While the work done on a body is the dot product of the translation force and the position vector.
• Pretty sure work and torque are $Nm$, not $N/m$. – noah Feb 24 '19 at 14:41