If you remember nothing else: the abstract is a preview, and the introduction is a setup. One tells you what happened, the other tells you why it needed to happen. They’re not interchangeable—they’re partners with very different roles.
Descriptive and Informative Abstracts
Think of a murder mystery novel. The abstract is the blurb on the back cover: “A detective finds a body in a locked room. Only three people had keys. One of them is lying.” The introduction is the first chapter: the rainy night, the detective’s coffee mug, the phone ringing, and that first step into the mansion. Both are necessary. Both serve the story. But they are not the same thing.
