There is considerable ambiguity in the terminology used to describe the different parts of a battery pack, most likely because alkaline cells are commonly referred to as "batteries", and we frequently forget that a car starter battery is made up of six cells.
The most fundamental component of a battery is the cell, which provides 3 to 4 volts in the case of lithium-ion (Li-Ion) batteries.
A group of cells with direct parallel wiring that also supplies 3V to 4V;
A physical module comprises several cells (or blocks) connected in series to produce a higher voltage (such as a battery module with four cells connected in series to produce 12V nominally).
A collection of batteries, arranged in any series and/or parallel combination.