What is the difference between Task and Thread in C#, and when would you deliberately choose one over the other?

A Thread represents a genuine, independent OS-level execution path, giving fine-grained control (priority, explicit lifetime) but consuming real system resources per thread and requiring manual synchronization if shared state is involved -- appropriate for long-running, dedicated background work needing direct control. A Task is a higher-level abstraction over the thread pool, automatically reusing pooled threads rather than creating new ones per operation, and integrates natively with async/await, making it the preferred choice for short-lived, scalable, I/O-bound work like web requests, file access, or API calls.

// Thread: a dedicated, manually managed execution path
Thread thread = new(() => Console.WriteLine("Running in a thread"));
thread.Start();

// Task: uses the thread pool automatically, integrates with async/await
await Task.Run(() => Console.WriteLine("Running in a task"));