Sample app contains commented code in dashboard.js. This code blocks main thread for 10 seconds, if you uncomment it - you will see that app becomes frozen for 10 seconds:
Web Worker is defined in dashboard.js. Web Worker is a separate JS file, which is being used for Worker object. API allows to send and receive messages, this way we can communicate to and from Web Worker (start a new task and receive message when task is completed): Read the complete article here.
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