Aggravated burglary = illegally entering a dwelling while armed with a deadly weapon (or words to that effect). It's like armed robbery + breaking and entering, sort of. Some states have supplemented that with "home invasion" charges, which just adds a "dwelling was occupied" element to the burglary.
Armed robbery would be a more applicable charge if the victim were accosted and threatened while out on the street, basically anywhere outside their house or apartment.
In Missouri “Armed Criminal Action” would be added to the list of charges.