I know this may be a silly question. I referred some articles. But, I am very interested to know the main difference for the following code,

```
using System;

namespace Business
{
    public class User
    {
        private int _id;

        public int ID
        {
            get { return _id; }
            set { _id = value; }
        }
    }
}

```

And

```
using System;

namespace Business
{
    public class User
    {
        public int ID { get; set; }
    }
}

```

I want to know some brief details (any reference)...

Thanks