12th of 20 Questions.
What is a Web Worker and why do we need it? What problem does it solve in the browser?
A Web Worker is a script that runs in a background thread, separate from the main execution thread, solving the problem of blocking the UI during CPU-intensive tasks.
Web Workers allow JavaScript to run in background threads, preventing long-running computations from blocking the main thread (UI rendering, event handling). Without workers, heavy tasks like image processing, large data parsing, or complex calculations would freeze the page, leading to poor user experience.