## Wikipedia - Differenza finita (it) change of a quantity

https://doi.org/10.1351/goldbook.C00968
The increment of the value of a quantity $$Q$$ with time. The change may be expressed either infinitesimally at time $$t$$ by the differential $$\text{d}Q$$ or $$\text{d}Q(t)$$, or in practice it may be expressed by a finite increment over the time interval $$(t_{1};t_{2})$$, i.e. $$Q(t_{2})- Q(t_{1})$$, which may be written $$\Delta Q$$ or $$\Delta Q(t_{1};t_{2})$$ $\Delta Q = \Delta Q(t_{1};t_{2}) = Q(t_{2})- Q(t_{1})$ Examples are: mass change, $$\Delta m$$; @A00297@ change, $$\Delta n$$; volume change, $$\Delta V$$; @S06072@ change, $$\Delta c$$.
Source:
PAC, 1992, 64, 1569. (Quantities and units for metabolic processes as a function of time (IUPAC Recommendations 1992)) on page 1571 [Terms] [Paper]