What does cell-to-cell variability means?

Question

I'm reading an article where they claim that transcriptional bursting could play a role in cell-to-cell variability.

Cell-to-cell variability plays a critical role in cellular responses and decision-making in a population, and transcriptional bursting has been broadly studied by experimental and theoretical approaches as the potential source of cell-to-cell variability.

I was looking for a definition of Cell-to-cell variability and I found only the one of Single-cell variability

In cell biology, single-cell variability occurs when individual cells in an otherwise similar population differ in shape, size, position in the cell cycle, or molecular-level characteristics. Such differences can be detected using modern single-cell analysis techniques. Investigation of variability within a population of cells contributes to the understanding of developmental and pathological processes.

Answer 1

I won't ask a question that's related to an article before reading it completely! The answer was in the first paragraph.

Cell-to-cell variability defined as when genetically identical cells in an identical environment behave differently, leading to significant consequences in many biological processes from bacterial decision-making to mammalian development.