This is a blockquote
Use blockquotes when you are quoting something verbatim that is longer than a line or two (if it is shorter than that, you can just put it "in quotation marks"). You should do this whenever you quote verbatim from anything, whether that is an online article, a scripture, or a published fable. Also remember to include a reference to the thing you are quoting from, and, if you know of somewhere it is available online, a link to the online version.
Avoid using blockquotes when you are paraphrasing. For example, if your parents told you the story of Narasimha, and you then find a question here about Narasimha that you would like to answer, you should not put your recounting of the tale of Narasimha in blockquotes, because it is not a verbatim quote from anything. What you should do is include a note in your answer that says something like "This answer is based on the story of Narasimha, as told to me by my parents". Of course, ideally, we would like to draw from original writings (e.g. scripture) as much as possible, but it's understandable if there are cases where that isn't possible/feasible.