Is a night-mooring near maple bridge a seven-character quatrain or a seven-character poem?

Seven-character quatrains. Seven-character quatrain is a form of poetry, which consists of four sentences and seven words and belongs to the category of metrical poetry. "a night-mooring near maple bridge" accurately and delicately describes a passenger's observation and feelings about the night scene in late autumn in the south of the Yangtze River. Each sentence is seven words in form, which conforms to the structural characteristics of quatrains. A quatrain usually needs a short space to express a complete meaning, and this poem just meets this requirement.