The pilcrow, ¶, is a typographical character that marks the start of a paragraph. It is also called the paragraph mark (or sign or symbol), paraph, or blind P.
The pilcrow may be used at the start of separate paragraphs or to designate a new paragraph in one long piece of copy
The pilcrow was a type of rubrication used in the Middle Ages to mark a new train of thought, before the convention of visually discrete paragraphs was commonplace.