Burglary and Robbery are synonyms by english definition. However, legally burglary is defined as entering a home or building with the intent of stealing property. Robbery is legally defined as taking of property from a person's body or in the person's immediate presence. Robbery can be done anywhere whereas burglary involves entering a home/building.
I'm sure there's been many instances of legal argument when a burglary constitutes a robbery when someone is in the house. If someone is in their bedroom asleep and someone breaks in and takes their TV and leaves, as an example, that would probably only be charged as burglary. If that person comes out of the bedroom and confronts the thief, it now becomes robbery if the owner intercedes.
Maybe it makes a difference in court due to the punishment I don't know since I am not a criminal lawyer.