The title refers to the name of a book or composition. A unit implies that the text is a single and complete component of the writing, but that can be part of a larger and more complex whole. A chapter is the main division of a book, and it usually consists of a number of title. A chapter subheading is a heading given to a subsection of a piece of writing, which contains details about what the following text is about. A topic sentence identifies the central idea of a paragraph. Finally, the text words develop the idea or provide evidence for the topic sentence.
