What's the difference between creating a new instance with "new() and ".StartNew()"?

Question

Coming from my "answer" to question "Stopwatch in a Task seems to be additive across all tasks, want to measure just task interval"

What are the possible differences between creating a new Stopwatch instance as:

Stopwatch timer = System.Diagnostics.Stopwatch.StartNew();

with

Stopwatch timer = new Stopwatch();
timer.Start();  

Implied subquestion:
Why was StartNew() method provided?

Answer 1

It initializes a new System.Diagnostics.Stopwatch instance and sets the elapsed time property to zero, and starts measuring elapsed time

and save the one line code to implicitly calling Start() method