Here's a breakdown:
* Architrave: This is the lower part of the entablature, and in the Doric order, it consists of three horizontal bands.
* Frieze: The middle part of the entablature is the frieze, which is often decorated with triglyphs (vertical blocks) and metopes (rectangular spaces between the triglyphs). These spaces could be left plain, or they could be adorned with sculptures.
While the Ionic and Corinthian orders also have three-part architraves, their friezes are different:
* Ionic order: The frieze is often decorated with a continuous band of sculpted figures or a scrolling pattern.
* Corinthian order: The frieze can be similar to the Ionic order, but it often features more elaborate and ornate carvings.
Therefore, the key characteristic that identifies the Doric order is its unique combination of a three-panel architrave and a decorated frieze with triglyphs and metopes.