An "introduction" is the beginning section of a piece of writing or a speech. It serves to present the main topic and provide context for the audience. An effective introduction captures attention and outlines what will be discussed, helping readers or listeners understand the purpose of the content. In academic writing, an introduction often includes a thesis statement, which summarizes the main argument or point of the work. In presentations, it may involve a brief overview of the key points that will be covered. Overall, introductions are essential for setting the stage for the information that follows.