Advantage of using thread start

Hi,
For threading what is the difference between these

1.With using Threadstart

Thread thread = new Thread(new ThreadStart(WorkThreadFunction));
thread.Start();

public void WorkThreadFunction()
{
try
{
// do any background work
}
catch (Exception ex)
{
// log errors
}
}

2. With out using Threadstart
Thread thread = new Thread(WorkThreadFunction);
thread.Start();

public void WorkThreadFunction()
{
try
{
// do any background work
}
catch (Exception ex)
{
// log errors
}
}

regards
krrish