Interviewer asked: Talk about your understanding of seo. How should you answer?

SEO is a tool, or an idea, and a means to get traffic through keyword ranking.

Simply put, you can get keyword rankings, exposures and orders through this tool.

What's more, by extension, we use various technologies to get traffic online, such as Baidu keyword ranking, Weibo hot search, headline explosion, WeChat official account 10w+ and so on, and then get conversion.

The working principle of search engine

Search engine is basically the first website we want to open when we open the browser. No one. Don't ask me why, because I am here. With the development of the network, more and more content is produced on the network, but how can we easily see it? This directly led to the birth of search engines. When we do seo network promotion, we must first know its working principle, and then we can pursue it in a targeted way, and finally achieve the promotion of website ranking. So what is its specific working principle?

The basic working principle of search engine includes the following three processes: first, search and collect web information in the Internet; At the same time, information is extracted and organized, and an index database is established; Then, according to the query keywords input by the user, the retriever can quickly check out the documents in the index library, evaluate the relevance between the documents and the query, sort the output results, and return the query results to the user.

Zac's book is written like this: grab, grab, preprocess and rank.

1, grab the web page. Every independent search engine has its own crawler. Spider crawls from one website to another along hyperlinks in web pages, and continuously visits and crawls more web pages through hyperlink analysis. Captured web pages are called web page snapshots. Because hyperlinks are widely used in the Internet, theoretically, most of the webpages can be collected from a certain range of webpages.

2. Process web pages. After a search engine captures a web page, it needs to do a lot of preprocessing before it can provide retrieval services. Among them, the most important thing is to extract keywords and establish an index database and index. Others include eliminating duplicate pages, word segmentation (Chinese), judging page types, analyzing hyperlinks and calculating the importance/richness of pages.

3. Provide retrieval services. Users input keywords for retrieval, and search engines find web pages matching keywords from the index database; In order to facilitate the user's judgment, in addition to the title and URL of the page, it will also provide information such as a summary from the page.

Crawl Crawl: Search engine spiders crawl web pages by following links, get the html codes of the pages and store them in the database. The spider here refers to the program used by search engines to crawl pages. After browsing the web pages on the network, this program will store the browsing records as raw data in the database. Generally, when spiders visit, they will first visit the robots protocol file in the root directory of the website to find out what can't be crawled and what can be crawled.

Then, in order to grab more content, spiders usually follow the links on the website, crawl the website directory in the order of depth first and breadth first, and then crawl the database.

After talking about spiders, the question is coming. How to attract spiders? Our most popular method is to go to the website submission portal of the search engine and submit our own website, so that the new website can be quickly accessed by spiders and capture the recorded data into the database for later use.

Pretreatment: This step is the arrangement of data in the database after spider crawls. First, extract the text, then divide the words, remove the stop words and eliminate the repetition. Finally, the ranking we see is based on the positive index and the negative index.

The calculation method of ranking is: processing search words, matching with database, initial data selection, correlation calculation, filtering and adjusting to the final ranking.

At this point, the whole work is basically over, and we look at it simply. In fact, the truth is not what we see, what we see is only the appearance, because we don't know the technology, but we need to understand the principle of spider's crawling and ranking, so that we can be handy in future optimization.

The working principle of search engine