Which statement best describes a web worker’s execution?

Which statement best describes a web worker’s execution?

• A. It runs in the main thread to accelerate rendering
• B. It runs in the background without blocking the main UI
• C. It runs on the server to generate pages
• D. It runs as a plugin within the browser

Answer: (B)

Web workers run code in a separate background thread from the main UI thread. This separation lets them perform heavy computations or data processing without blocking the user interface, so the page remains responsive while work continues in the background. They don’t have direct access to the page’s DOM and communicate with the main thread only by sending messages back and forth. They’re created by the main script, run in their own isolated context, and can load additional scripts if needed. They’re not server-side and not browser plugins.

Web workers run code in a separate background thread from the main UI thread. This separation lets them perform heavy computations or data processing without blocking the user interface, so the page remains responsive while work continues in the background. They don’t have direct access to the page’s DOM and communicate with the main thread only by sending messages back and forth. They’re created by the main script, run in their own isolated context, and can load additional scripts if needed. They’re not server-side and not browser plugins.