Demographic = shifts in birth/death rates with development. Epidemiologic = shifts in main causes of death (infectious to chronic).

I wasn't familiar with the 'Epidemic Curve' but this teaches me the graph shows cases over time and helps identify an outbreak pattern

This section explains incidence = new cases (risk of getting disease). Prevalence = all cases (burden of disease). Relationship: Prevalence ≈ Incidence × Duration.

This paragraph explains counts = raw numbers. Ratios = compare two numbers. Proportions = part/whole (%). Rates = ratio that includes time (often per 100,000).