Are .NET threads different from operating system threads?

Question

1. Are .NET threads lightweight user-mode threads or are they kernel-mode operating system threads?

2. Also, sparing SQL Server, is there a one-to-one corresp

Answer 1

.NET's threads are indeed abstractions, but you can basically think of them as nearly identical to OS threads. There are some key differences especially with respect to garbage collection, but to the vast majority of programmers (read: programmers who are unlikely to spin up WinDBG) there is no functional difference.

For more detail, read this