Understanding Office by Wiki

An office is generally a room or other area where people work, but can also denote a position within an organization with specific functions associated with it (see officer, his official title), the latter is in fact a previous office use such as place originally referring to the location of duty. When used as an adjective, the term "office" can refer to business-related tasks. Legal, writing a business or organization has offices in any place that he has an official presence, even if that presence is in, for example, a storage silo rather than an office.

Office Work - Example Office by Wiki

An office is an architectural and design phenomenon and a social phenomenon, it is a small office such as a bank on the corner of a "mom and pop shop" of extremely small size (see Office / Home Office small) through entire floors buildings up to and including massive buildings dedicated entirely to a single company. In modern terms an office usually refers to the location where white-collar workers are employed.