Learn about search engine-search engine technology

Among all network promotion methods, search engines are the most talked about, and our promotion journey will start from here.
Indeed, search engines are a powerful weapon for online promotion and are free-but we must first understand them.
We need to know how they work, how they are classified, how they are queried ...... And the search engines are different from each other, so we also need to understand their personality for the particularly important engines.
1. Two basic terms:
SearchEngine: by running a software, the software automatically obtains a large number of site page information through various links on the network and sorts the information according to certain rules to form a database, for query. Such a site (obtaining information ==> organizing and establishing a database ==> providing queries) is called a "search engine ". The software used is generally called "Spider" and "crawlers.
Directory: manually classify websites and create a database to provide queries. Such sites are called "classification Directories ". Typical search engines such as AltaVista, Excite, HotBot, and Inktomi, and the most important classification directory is Yahoo.
In fact, no matter "search engine" or "classification directory", the goal is the same: to obtain website information and create a database to provide query. However, the method used is different.
Because the "search engine" relies on software for automatic execution, its database capacity is very large, but the query results are often not accurate enough. Because the "classification directory" relies on manual classification, the information obtained from the query must be accurate, but the collected content is very limited.
We usually refer to these two types as "search engines". In the following discussion, we will focus on "automatic" search engines, such as Yahoo, I will discuss it separately in "Chinese Yahoo.
2. Main search engines:
Seven major search engines and their respective pages: engine Alta Vista Northern Light Inktomi Excite Lycos Infoseek Web Crawler page (millions of pages) 1501251105550452 (The above data is the February 1, 1999 statistical value)
3. Search engine three steps:
The first step is that the "Spider" software accesses a site and reads the page of the site through the link. The "Spider" will automatically return to the site from time to check the changes; the site information obtained by the "Spider" forms a huge network information library, just like the backup of the Accessed site on the entire network, of course not all the content is recorded. This is what we call the database. The third step is to query the service. This is achieved through the query software. When you enter the query content, the software will find the relevant content in its database and sort it according to its rules.
4. How is the search engine ranked during Query? The most important reason is the correlation between the content of a site and the query term. But how is the content search engine of a site determined? -- Title, Keywords, Description, content at the beginning of the page, and the degree of association between the content itself. In addition, most search engines currently support AG.
Another major factor is the degree of association of a site across the network, that is, the number of times that other sites on the network appear (LinkPopularity ).
Although different search engines have their own "game rules", remember the word "degree of association", including intra-site and off-site (entire network ).