how can class Head access class Tennis?

Hello

By default, a class is private. So i don't understand that this line Tennis player = new Tennis(); can be exectuted. It would not be able to reach the class Tennis.

Thanks

class Tennis
{
    public string name;
 }

class Head
{ 
        static void Main(string[] args)
        {
            Tennis player = new Tennis();
             ...
        }

}