Not all on-page elements are as important as others—search engines must assign particular importance or weight to various on-page factors. A webpage's title tag, for example, is widely considered to be a strong indicator of the subject matter of a webpage. As such, a title tag has a very strong influence on search rankings. Conversely, the filenames of the images on a webpage, such as texas_web_marketing.jpg, would not necessarily be a strong indicator of the subject matter of a webpage. So, search engines apply much less weight to image file names in their ranking algorithms. The basket of on-page factors that influence search engine rankings are afforded a wide variation in influence in search engine rankings—this variance is referred to by SEO professionals as weight. Title tags and heading tags are afforded greater weight, while image filenames, alt tags (text tags that accompany images), and bold text are given less weight. That is not to say that bold text and image filenames are not important. In fact, it's the use of these lower-weight attributes that can give a webpage the extra push to higher rankings. When all of the ranking factors are present and utilized effectively and combined with a sound program of developing inbound links, the effect is almost supernatural—the combined effect of all factors working together can develop tremendous ranking power.