Difference between Integrated Security SSPI vs True

We can use two kinds of Authentication to connection SQL Server namely SQL Server Authentication and Windows Authentication. To force Windows Authentication, we normally use either the parameter Integrated Security=True or Integrated Security=SSPI. But some of us(at least people I know) don’t know what is real difference between Integrated Security SSPI vs True.

After I have analyzed some time in web, found following tips.

Actually they are not the same or interchangeable, Microsoft says they are equivalent but that doesn't mean interchangeable or that they are the same thing. TRUE ignores User Id and Password if provided and uses those of the running process, SSPI it will use them if provided which is why MS prefers this. They are equivalent in that they use the same security mechanism to authenticate.

Source: http://stackoverflow.com/questions/1229691/difference-between-integrated-security-true-and-integrated-security-sspi#comment-6483379

Thanks,
Morgan
Software Developer