Explain whether Flutter operates in a single-threaded mode and how it performs task execution.

Flutter mainly works in a single-threaded mode, using the main isolate for executing UI code. All rendering and event handling operations are performed in this isolate.

For executing heavy or long tasks, Flutter allows creating additional isolates — separate threads with their own memory, which do not block the main thread. You can also use asynchronous operations (Future, async/await) for non-blocking task execution.

Thus, Flutter ensures interface responsiveness by running UI in the main isolate and delegating heavy computations to background isolates or asynchronous operations.