C#: What is the difference between Task.Run and Task.Factory.StartNew in C#?

Task.Run — simple, recommended. StartNew — advanced, flexible.

Task.Run:

• Simple API.
• Uses TaskScheduler.Default.
• For CPU-bound work.

1// Simple
2await Task.Run(() => {
3    // CPU-bound work
4    Thread.Sleep(1000);
5});

Task.Factory.StartNew:

• More options.
• Can specify scheduler.
• Can specify creation options.

1Task.Factory.StartNew(() => {
2    // Work
3},
4CancellationToken.None,
5TaskCreationOptions.LongRunning,
6TaskScheduler.Default
7);

Key differences:

• Task.Run — simpler, safer.
• StartNew — more control.
• Task.Run — always uses default scheduler.
• StartNew — can specify scheduler.

Best practice:

• Use Task.Run for most cases.
• Use StartNew only when needed.