What names did Allah teach Adam, 2:31?

> And He taught Adam the names, all of them; then he presented them to > the angels, and said, "Tell Me the names of these, if you are > sincere." (2:31) > He said, "O Adam, tell them their names." And when he told them their > names, He said, "Did I not tell you that I know the secrets of the > heavens and the earth, and that I know what you reveal and what you > conceal?" (2:33) 1. What names is Allah (SWT) referring to? His own names? Name of the Angels? or there is any other names? 2. Why did Allah felt the urge to confront with Angels regarding creation of prophet Adam (PBUH) ?