The inclusion effect of search engines is the very survival basis for most websites. This statement is not exaggerated at all. If a site is purely optimized naturally, in the long run, it will naturally become more and more effective, and there's nothing wrong with that. However, the problem arises when one either doesn't know or only learns some superficial techniques and then applies them extensively, violating search engine rules, which leads to a significant decrease in the number of pages indexed. If the number of indexed pages decreases, how can one apply to Google for re-inclusion? The Google Webmaster Blog has provided a special topic explanation regarding this issue.