When we enter any word or when we enter any query in search engines to search, and when we press Enter key, we get a list of results that contains almost query terms we are searching for. We this list is presented in front of us, normally we click on the top links in the lists because they seem more relevant to our queries. Here the point to be noted is that “How these sites are coming on the first page of results?”. Yes this is because of powerful web marketing technique that is called Search Engine Optimization abbreviated as SEO.
As we know that there are millions of websites on the Internet, and thousands are also launched daily, so overall websites are increasing day by day. Search Engine Optimization (SEO) is the only technique which helps all the search engines to rank a website. SEO also helps to get high traffic from the search engines. So we can say that SEO is the name of different techniques used to rank high of a website. SEO is not a single technique name it is combination of different techniques. Later you will see all those different techniques which are included in a term SEO.
In this Tutorial you will know about Search Engine Optimization – What is SEO – How does it work and what is the ranking criteria of major Search Engines.
How Search Engines Work
Before going to learn that how search engines work, it is important to keep in mind that Search Engines are not humans and they do not see a web page as we see with our eyes. Unlike humans, search engines are text driven. Search engines crawl a web page and see at particular points and items mainly text go know about the detail of a web page. Search engines crawl a page and perform several other activities to list a web page in search results. Other activities are indexing, processing, calculating relevancy and retrieving etc.
Crawling is the first process which is performed by search engines. In this process search engines crawl a web page to see that what is there. This process is performed by a specific software known as “crawler” or “spider” (In case of Google, Google-bot is crawler ). Crawlers follow links from one page to another and index all the things coming in their way. They keep in mind the number of pages on the web (over 20 million), it is difficult for a crawler to see a site daily to know if a new page has appeared or an existing page is modified.
After the completion of crawling process, next step is indexing of contents. The indexed page is kept in giant database, from where it is retrieved. Indexing process identifies the words and expression that describes the page and assigning the page to particular keywords. Indexing is a very complex task and it is not possible for human to perform this sensitive task. Search Engine’s crawler can perform this particular process in better way. But sometimes crawlers can not describe a page better, we can help them to understand the description of a page by optimizing it. By doing this optimization process we can tell correct description of page to search engines, so we can get better ranking and traffic as well. We will also cover this optimization process.
When a search term comes from user interface (Search Box), search engine processes it. It compares the search strings with the data available in its database. Since it is likely that more than one page contains the same search term, the search engine starts calculating the relevancy of each of the pages in its index with the search strings.
There are various algorithms to calculate relevancy. Each of these algorithms has different relative weights for common factors like keyword density, links, or meta-tags. That is why different search engines give different search results pages for the same search string. What is more, it is a known fact that all major search engines, like Yahoo!, Google, Bing, etc. periodically change their algorithms and if you want to keep at the top, you also need to adapt your pages to the latest changes. This is one reason (the other is your competitors) to devote permanent efforts to SEO, if you’d like to be at the top.
The last step in search engines’ activity is retrieving the results. Basically, it is nothing more than simply displaying them in the browser – i.e. the endless pages of search results that are sorted from the most relevant to the least relevant sites.
Differences Between the Major Search Engines
The basic principle of operation of all the search engines is almost same, but there are some minor differences between them which cause huge difference in search results there. There are different factors which have different importance for different search engines. There were times, when SEO experts joked that the algorithms of Bing are intentionally made just the opposite of those of Google. While this might have a grain of truth, it is a matter a fact that the major search engines like different stuff and if you plan to conquer more than one of them, you need to optimize carefully.
Here i would like to list some differences between the Search Engines. For example, for Bing and Yahoo!, on-page keyword factors are of primary importance, while for Google, links are of huge importance. Google sees the sites like wine, the older, the better, in contrast Yahoo! normally has no expressed preference towards sites and domains with tradition (i.e. older ones ). This is why a site take some time to go at the top in Google Search Engine.