From the initial creation of "web bridges" and hidden text to the current use of hidden links, and even building a massive link farm - LINK FARM - to generate a large number of useless links. Some go as far as using hacking techniques to infiltrate GOV websites and add hidden links because GOV websites generally have higher authority. Others engage in blog group construction, forum group promotion, and spamming comments with mass tactics, all aimed at increasing external links to their sites. These various cheating methods are used for this purpose. More legitimate approaches include purchasing links, reciprocal links, and acquiring one-way links through reputation. The author believes that using cheating methods on experimental sites can also be considered a form of testing, but would you use such cheating methods on your beloved legitimate site? For me, the answer is no. Those who have been penalized by search engines should understand how unpleasant it feels to be punished by them...