Zoom lenses and cameras with superzooms are often sold with a times ("×") zoom number — like a 12× zoom or 30× zoom.
There are different uses of magnification ratios. In the context of zoom, it refers to the ratio of max to min focal lengths. An 18-200mm lens has 200/18 = 11× zoom.
But how does ×-zoom relate to magnification, when used for macro or just to make something far away look bigger?
In the context of macro, the multiplier refers to the (inverse of the) reproduction ratio, which is size on sensor : life size. For instance, I have a macro lens where the max reproduction ratio is 1:1, or 1×. I also have several zooms capable or 1:4 to 1:2 ratios... 0.25× to 0.5×.
How can two 70-200mm lenses have different magnification?
Lenses with different focal lengths can have different reproduction ratios based on their minimum focusing distance. (I don't know the math involved.) Similarly, lenses with different focal lengths can have the same reproduction ratios.
At a given reproduction ratio, the focal length affects the working distance. Consider 35mm and 100mm macro lenses with 1:1 reproduction ratios. Because the subject, although magnified by the same amount, is at different distances from each lens, the perspective portrayed in the resulting images is different. It is also more difficult to light subjects with the 35mm lens because the lens blocks light from reaching the subject.