The principle of optimizing keyword ranking in SEO is to go through several processes to rank a website's web pages with keywords on the first page. These processes include website creation, content creation, TDK (Title, Description, Keywords) setting, URL production, URL submission, Baidu crawling, successful crawling, attracting Baidu spiders, entering Baidu sandbox, initial review of content quality by Baidu, indexing if the content is of high quality, ranking based on Baidu's algorithm, and a series of optimization measures to appear on the first page of user searches.

To understand the principle of SEO keyword ranking optimization, it is important to consider the following points:

1. Optimization target: The optimization target is the specific web pages of a website. The more web pages a website has, the more keyword rankings it can have (assuming the TDK is set correctly). However, it is important to note that a page cannot have rankings for multiple keywords with different meanings. Therefore, the number of indexed web pages is a key factor in SEO.

2. Website snapshot: A website snapshot is a backup of a web page's content stored by search engines. It is updated regularly based on the quality of the website. The snapshot is used to analyze the quality of a website and ensure the accuracy of rankings.

3. Hyperlink analysis: Hyperlink analysis is a patented technology used by search engines, including Baidu. It evaluates the quality of linked websites by analyzing the number of links to them. The higher the quality and popularity of a page, the higher it will rank.

4. Related recommendations: Related recommendations refer to internal linking within a website. For example, if a user visits a page about camera pictures, related recommendations can include links to pages with camera parameters, camera product purchase pages, or camera manufacturer introduction pages. This improves user experience, increases visit duration and depth, and enhances the trustworthiness of the web page in search engines.

5. Backlinks: Backlinks are links from other websites to a particular web page. The quality and relevance of backlinks are important factors in ranking. The value and relevance of a backlink can vary based on the website it is from and the page it is linked to. It is important to have relevant and high-quality backlinks, while avoiding a large number of irrelevant backlinks.

In conclusion, optimizing keyword ranking in SEO involves various processes and considerations such as website creation, content creation, TDK setting, URL production, URL submission, Baidu crawling, content quality evaluation, indexing, ranking, and optimization measures.