The Google Webmaster Guidelines are those that define the appropriate behavior that websites should follow to make their sites better-ranked or crawled. Other search engines such as Bing have their own webmaster guidelines similar to the principles established by Google.
Recommended Reading: Google Webmaster Guidelines
Within the Google Webmaster Guidelines, there are two types: the General Guidelines and the Quality Guidelines.
They are those that contain rules and conditions that show how Google works to understand the pages and index them; with them, you can know how to improve the pages and how to perform search engine optimization. They also include tips and useful tools to improve the visitor experience.
According to Google, some of the General Guidelines may be:
They are only those that explain which are the deceptive tactics used to manipulate the SERP that can cause serious violations penalized by Google and how to avoid them.
Some of these tactics that are prohibited to use in Google are:
Google makes available to webmasters the "Webmaster Guidelines," which are a set of rules, tips, and tools used to learn how to optimize websites for the purpose of optimal ranking and crawling by search engines.
It is important to note that Google's overall purpose is to link websites with relevant content in search results, the better the sites, the more satisfied users will be and the more confident they will be using Google as a search engine, thus generating a greater source of revenue from the advertising displayed in organic web search. This is why the "Webmaster Guidelines" are used, which seek to guarantee the quality of the websites' content and avoid that SEO only optimizes the classification within the search engine and does not achieve user satisfaction.
If websites do not comply with Google's guidelines, they can be sanctioned individually, a directory or a domain; this would affect the site's ranking and could decrease the visibility in the SERP. These sanctions are mostly temporary and can be fixed by, for example, removing web spam.