The disconnect() method of the PerformanceObserver interface is used to stop the performance observer from receiving any performance entry events.
The observe() method of the PerformanceObserver interface is used to specify the set of performance interface types to observe. The performance observer's callback function will be invoked when a performance entry is recorded for one of the specified types.
The PerformanceObserver() constructor creates a new PerformanceObserver object with the given observer callback. The observer callback is invoked when performance entry events are recorded for the entry types that have been registered, via the observe() method.