The Equals Sign in Gauss' Magnetic Law
The Equals Sign (=)
The Equals Sign (=) in Equation 2, or Gauss' Magnetic Law, means the quantities on the left and right side are identical.
The Equality Sign in Gauss' law is a scalar equals - which means the quantities on either side are single numbers. This is distinct from the equal signs in the last 2 Maxwell's Equations, where the equality is a 3-dimensional vector equality.
OK - we have equality of a scalar quantity, but it should also be noted that the equality forces not just the values to be equal, but also the units or dimensions. And the units of Gauss' Magnetic Law are Webers per meter cubed [Wb/m^3]. This can be thought of as Magnetic Charge per volume. And isolated Magnetic Charge has not been discovered yet, which is why the right side of this equation is zero.