A paragraph (from Ancient Greek παράγραφος (parágraphos) 'to write beside') is a self-contained unit of discourse in writing dealing with a particular point or idea.
The purpose of a paragraph is to express a speaker’s thoughts on a particular point in a clear way that is unique and specific to that paragraph. In other words, paragraphs shouldn’t be mixing thoughts or ideas. When a new idea is introduced, generally, a writer will introduce a new paragraph.
A paragraph is a section of text that pertains to a single theme and is designated by an indent or a line break. Paragraphs are at least one sentence long and are usually one part of a larger whole.