A chancery is the principal office that houses a diplomatic mission or an embassy. This often includes the associated building and the site. The building can house one or several different nations' missions. The term derives from chancery or chancellery, the office of a chancellor. Some nations title the head of foreign affairs a chancellor, and 'chancery' eventually became a common referent to the main building of an embassy.
The term "embassy" technically or historically refers to the ambassador's residence and not their office, although their residence and office were often collocated. Among diplomats the terms "embassy residence" and "embassy office" is used to distinguish between the ambassador's residence and the chancery. In some cases, an ambassador's residence and the business office are still located in the same building.