Final answer:
A differential white blood cell count provides information about the relative percentages of different types of white blood cells in a person's blood.
Step-by-step explanation:
A differential white blood cell count provides information about the relative percentages of different types of white blood cells in a person's blood. It helps to identify any abnormalities in the composition of white blood cells and can indicate whether a person has a disease. For example, an increase in the percentage of neutrophils may suggest a bacterial infection, while an increase in the percentage of lymphocytes may indicate a viral infection. The total white blood cell count, on the other hand, only provides information about the total number of white blood cells in the blood without distinguishing between cell types.