To
understand SEO, we should have knowledge about ARCHITECTURE
of
search
engines.
Note:
As
we have various search engines, each search engine have its own
principle components.
Here
are the main components of Google search engine:
- Spider
- Crawler
- Indexer
- Data Base
- Results Engine
- Web Server
Spider
also
known as Search
Engine Robots.
- This is a program , it downloads web pages (just like a web browser) .
- The difference is that the browser displays the information presented on each page(text, graphics, etc) while a spider doesn’t.
- A Spider works directly with the underlining HTML code of the page.
Crawler
- This is a program, finds all the links on each page. Its task is to determine where the Spider should go either by evaluating the links (or) according a pre-defined list of addresses(Home Page, Contact page).
- The Crawler follows these links and tries to find documents not already known to search engines.
In
SHORT,
- Crawler finds the links.
- Crawler guides Spider to follow the links.
- Mainly Crawler finds the documents which are New (unknown things).
Note:
Crawler reads from left to right, top to bottom.
Indexer
- This program analysis each page and analysis various elements such as text, headers, structure of stylistic features, special HTML tags (like all HTML tags)etc.
Data
Base
- This is a storage area for the data that the search engine downloads and analysis. Sometimes it s called the “Index of the Search Engine”.
Results
Engine
- Results Engines, ranks pages which it determines which pages best match a users query and in what order the pages should be listed. This is done according to the ranking algorithm of search engines.
- It follows the Page Rank, which is a valuable and interesting property and any SEO specialist is most interested in it when trying to improve his site search results.
Web
Server
- The search engine Web Server usually contains a HTML page “with a input field” where the users can specify the search query he/she interested in.
- A Web Server is also responsible in displaying search results to the users in the form of a HTML page.
Note:
More page rank indicates trusted and user friendly website.
