Task.Factory.StartNew vs Async methods

Might be a trivial question, but it might help me in basic understanding.

Is there any important difference between two following implementations?

1. Task.Factory.StartNew:

   public Task<string> ReadAllTextAsync(string path) {
       return Task.Factory.StartNew(() => File.ReadAllText(path));
   }
   

2. Async method on StreamReader:

   public async Task<string> ReadAllTextAsync(string path) {
       using (var stream = File.OpenRead(path))
       using (var reader = new StreamReader(stream)) {
           return await reader.ReadToEndAsync();
       }
   }