Something like that, although "applied" and "actual" are just one of ways describing it. Broadly speaking when you have current i flowing through a resistance R, and you measure voltage on the contacts, it will be -iR. Ideal battery has no internal resistance, so it always produces the same voltage, but no practical battery is ideal, so they all behave as if their voltage was lower under load.

Knowing the internal battery resistance is necessary to estimate the measurement error of the voltage, but as typical digital voltmeter has internal resistance in the 10 MΩ range, and typical battery (like AA) has an internal resistance in the single Ω range, it rarely really matters.