Run Multiple Tasks Without Freezing

My [app] needs to run several long tasks at once: [list your tasks, e.g. download files + process images + sync data]. Right now they run one after another and the UI freezes the whole time.

Create a system that:
- Runs each task on its own background thread (or uses a thread pool)
- Shows individual status for each task (waiting / running / done)
- Keeps the UI fully responsive throughout
- Updates the screen safely from background threads (no crashes)
- Handles errors in one task without stopping the others

My stack: [your language and framework here]

I'm learning, so explain each part simply.