Understanding the working principle of search engines will have a great help to our daily search applications and websites.
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■ Full-text search engine In the Search Engine Classification section We mentioned the full-text search engine to extract information from the website to establish a web database. The auto information collection function of the search engine is divided into two. One is a regular search, that is, every time (such as Google is generally 28 days), the search engine actively dispatches the "spider" program, retrieves the interconnected website within a certain IP address, once found new website, it will automatically Extract the information of the website and the URL to join your own database. The other is to submit a website search, that is, the website owner actively submits to the website. It is scheduled to send a "spider" program to your website (2 days to several months.) To scan your website and will The information is stored in the database for user query. Since the search engine index rules have changed significantly in recent years, the initiative to submit the website does not guarantee that your website can enter the search engine database, so the best way to get some external links, so that the search engine has more opportunities to find you And automatically include your website. When the user finds information with keyword, the search engine searches in the database. If you find a website that is consistent with the user's requirements, use a special algorithm - usually according to the level of matching of keywords in the web page, location / frequency , Link quality, etc., calculate the correlation and ranking level of each page, and then returns these web links to the user according to the low correlation degree. ................................................ .................................... ■ Directory index compared to the full-text search engine, directory index There are many differences. First, the search engine belongs to the automatic website search, and the directory index is fully dependent on manual operation. After the user submits the website, the directory editor will personally browse your website, and then decide whether to accept your website in accordance with a set of self-defined criteria and even editors. Second, when searching for the website, as long as the website itself does not violate the relevant rules, it is generally available to success. The directory index is much higher, sometimes it is not necessarily successful even if you log in multiple times. Especially like Yahoo! such super index, login is more difficult. (Due to the biggest difficulty of logging in Yahoo!, it is also a business network marketing, so we will introduce the skills of logging in to Yahoo Yahoo later later) In addition, when you log in to the search engine, we generally don't have to consider the website. Classification issues, while logging in to the directory index, you must put the site in a Directory. Finally, the information about each website in the search engine is automatically extracted from the user web page, so the user's perspective, we have more autonomy; the directory index requires manual to fill in the website information, and there are Various restrictions. What's more, if the staff thinks you submitted to the website's directory, the website information is not suitable, he can adjust it at any time, of course, it will not discuss with you in advance. Directory Index, as the name suggests in the corresponding directory, so the user can select keyword search when query information, or look up by layers by classification directory. If the result of the returned result is the same as the search engine, it is only more than some of the information. If you are looking for a hierarchical directory, the ranking of the website in a directory is determined by the order of the title letter (also exception). Currently, the search engine is integrated with the directory index. It turns out that some pure full-text search engines now also provide directory search, such as Google provides classified queries to Borrow Open Directory directory.
