Poetic liberties allow a scribe license to make the form fit the mood and meaning of a poem. Unlike prose, poetry has room for variation in line length, sentence structure, and punctuation.
The term enjambment is the running on of a thought from one line, couplet or stanza to the next without a syntactical break.
It originates from Nineteenth Century French poetry literally meaning a straddling, from enjamber to straddle.
The opposite of enjambment is end-stopped.