Understanding Properties

If this is

public string size;public string Size
{  
get { return size; } 
set { size = value; }
}

the same as this

public string Size
{ get; set; }

following this logic, why typing

Program.cs
Console.WriteLine(f.name);

Forest.cs

 public string Name
    { get; set; }

Error pops up ‘Forest’ does not contain a definition for ‘name’ . What happened to the “name” field? Or the field is supposed to have “Name” name, just like its property?