The common law definition of burglary is the breaking and entering of a residence at night with the intent to commit a crime. There are several elements involved, and all must be met to constitute a true burglary. In many respects, burglary is considered a more serious crime than robbery because it involves entering a residence, where one is deemed the most secure, and at night when one is presumably sleeping and therefore defenseless. Lesser forms of burglary might include entering a building other than a dwelling, or entering in the daytime; however true burglary can only be committed at night, and only in a dwelling. Robbery takes two forms: Armed Robbery, where money or goods is taken from another by means of force of arms. This is the typical robbery where a weapon is presented, and the victim ordered to hand over his wallet. The other form is Strong Arm robbery, also known as highway robbery, meaning one takes the money or goods of another but without force of arms. This can be done by assaulting the victim and taking his money, or even purse snatching.
The major difference here is that robbery is done face to face and burglary is not.
The crime of burglary involves entering someone's home illegally so as to commit a crime. In a burglary, the burglar is usually going to take something out of the house. But the burglar is not going to confront a person and take something directly from him or her.
By contrast, robbery is done in the presence of the victim. As the link below says, robbery is
taking of money or goods in the possession of another, from his or her person or immediate presence, by force or intimidation.
This means that robbery is something like mugging -- it is a crime in which the robber forcibly steals from a victim who is present at the time of the crime.