"Introductory" refers to something that serves as a beginning or an introduction to a subject. It often provides essential information or context that helps the audience understand what will follow. For example, an introductory course in a subject like mathematics lays the groundwork for more advanced topics by covering basic concepts and terminology.
In writing, an introductory paragraph sets the stage for the main ideas of an essay or article. It usually includes a hook to grab the reader's attention and a thesis statement that outlines the main points. This helps readers know what to expect and prepares them for the discussion ahead.