ReadonlydetailThe read-only detail property returns arbitrary metadata that was included in the mark upon construction (when using performance.measure().
ReadonlydurationThe read-only duration property returns a timestamp that is the duration of the performance entry. The meaning of this property depends on the value of this entry's entryType.
ReadonlyentryThe read-only entryType property returns a string representing the type of performance metric that this entry represents.
ReadonlynameThe read-only name property of the PerformanceEntry interface is a string representing the name for a performance entry. It acts as an identifier, but it does not have to be unique. The value depends on the subclass.
ReadonlystartThe read-only startTime property returns the first timestamp recorded for this PerformanceEntry. The meaning of this property depends on the value of this entry's entryType.
PerformanceMeasureis an abstract interface for PerformanceEntry objects with an entryType of "measure". Entries of this type are created by calling performance.measure() to add a named DOMHighResTimeStamp (the measure) between two marks to the browser's performance timeline.MDN Reference