1. Resting heart rate: The baseline heart rate at rest, which is usually lower than during physical activity. This point on the graph would typically show a relatively constant heart rate.

2. Peaks: These represent the highest heart rate reached during periods of physical activity or stress. These points on the graph would show spikes in heart rate.

3. Plateaus: These represent periods where the heart rate remains relatively constant during exercise or stress. The graph would show a horizontal line during these periods.

4. Recovery rate: This shows how quickly the heart rate returns to normal after physical activity or stress. After a period of increased heart rate, the graph would show a decline as the heart rate returns to resting levels.

5. Variability: The graph may also show variations in heart rate, such as short-term fluctuations or irregularities. These could be represented by jagged lines or sudden changes in heart rate.

Overall, the heart rate graph provides a visual representation of how the heart rate changes over time, illustrating the dynamics of heart rate during different activities or states of the body.