What’s the difference? They are all share similar traits. Keywords (KEY - WORDS) — are the important words that apply to your product, service or business and relate to what your audience is searching for online. Search words are the words or phrases that your audience is searching for online. And tags, are names, titles, or descriptions that apply to your image, text, object, download, file or web page that help online robots, AI, and search applications find your product, service or business. And while they are almost always similar and even repetitive, there are occasions to be unique.