Here's why:

* Interphase is the stage in the cell cycle where the cell grows, replicates its DNA, and prepares for division. It's the "in-between" period between two cell divisions.

* Cell division includes mitosis (for somatic cells) or meiosis (for gametes) and cytokinesis. These processes involve the separation of chromosomes and the division of the cytoplasm to create two daughter cells.

In summary: Interphase is about preparation, while cell division is the actual act of creating new cells.