Understanding thresholds
Thresholds are defined values that determine if a statistic is above, below, or within a normal range on your network.
Thresholds are also used when displaying colors in dashboards. Anything below the marginal threshold is blue, anything between the marginal and critical threshold is yellow, and anything above the critical threshold is red. Thresholds can also be used as part of status widgets that are based on either performance or a baseline.