Throughout the course of The Charge of The Light Brigade (a poem the based the Battle of Balaclava during the Crimean War), Lord Alfred Tennyson uses many poetic techniques such as imagery, intertextuality, rhyming, and meter to highlight loyalty leads to sacrifice.
It is not persuasion as it's not trying to convince you think about something in a certain way, and it's not informative as it doesn't have any dates, quotes, or references. You can also tell it's to entertain as it uses unique and emotional words.