I liked this definition of prose poem:
"Though the name of the form may appear to be a contradiction, the prose poem essentially appears as prose, but reads like poetry.[...]While it lacks the line breaks associated with poetry, the prose poem maintains a poetic quality, often utilizing techniques common to poetry, such as fragmentation, compression, repetition, and rhyme. The prose poem can range in length from a few lines to several pages long, and it may explore a limitless array of styles and subjects."
https://www.poets.org/poetsorg/text/...em-poetic-form