Julie, the "attending" is the patient's Primary Care Doctor; the doctor who is ultimately responsible for the patient. An "attending" is not an intern or a resident but a full fledged doctor who may be over a few interns or residents.
It kind of breaks down like a hierarchy:
1. The intern (the newbie)
2. The resident (the middle, still learning but not quite there yet)
3. "THE" doctor (attending) - the supreme being who knows all!
I couldn't help sharing the sequence of events since my oldest daughter is a brand spanking new "attending."