Introductory sections are the opening parts of a document, book, or presentation that set the stage for what follows. They provide essential background information, outline the main topics, and explain the purpose of the work. This helps readers understand the context and significance of the content, making it easier for them to engage with the material. In academic writing, for example, the introductory section often includes a thesis statement that presents the main argument or focus of the paper. It may also highlight key questions or issues that will be addressed, guiding the reader through the research or discussion that follows.