Magnitude difference refers to the numerical distance or gap between two values or quantities. It tells us how much larger or smaller one value is compared to another. Full definition
So, there's still at least an order of magnitude difference between observed ice loss and serious cause for concern. (realclimate.org)
I'm not claiming that the RDI are perfectly accurate, but as you will see we're really talking about orders of magnitude differences in nutrients as a proportion of the recommended daily intake. (optimisingnutrition.com)
Denebola has been classed as a Delta Scuti - type variable star (which vary in brightness by small amounts over periods lasting only hours and including radial as well as non-radial pulsations) as it exhibits small, Delta Sculti - type variability with around a 2.09 to 2.16 visual magnitude difference — in V on UBV Johnson system (Mkrtichian and Yurkov, 1998). (solstation.com)