string _username = string.Empty;
   string _password = string.Empty;

public string Username
{
    get { return _username; }
    set { _username = value; }
}

public string Password
{
    get { return _password; }
    set { _password = value; }
}

JobSeekerBO objBO = new JobSeekerBO();

public string _username = string.Empty;
public string _password = string.Empty;

JobSeekerBO objBO = new JobSeekerBO();
objBo.Username="someusername";
objBo.Password="myPassword";

public class JobSeekerBO
{
   string _username = string.Empty;
   string _password= string.Empty;

   public string Username
   {
        get { return _username; }
        set { _username = value; }
   }
   public string Password
   {
        get { return _password; }
        set { _password = value; }
   }
}

public class MailRepositary
{
  JobSeekerBO objBO = new JobSeekerBO();
  public MailRepositary()
  {
      objBo.UserName="works from constructor";
  }
  public void SomeMethod()
  {
      objBo.UserName="works from method also";
  }
}

var objBO = new JobSeekerBO();
var username = objBo.UserName;
var password = objBo.Password;

JobSeekerBO.UserName;

//accessing the non-public member of the class with the public property

JobSeekerBO objBO = new JobSeekerBO();
objBo.Username = "XXXXXXX";
objBo.Password = "XXXXXXX";

using XYZ;