COMPLETE
SEO COURSE
Chapter 1.
How search engine works?
When we discuss about SEO, first come first thing is Search engines, A search engine works by crawling, indexing, and ranking web pages to deliver relevant results to users based on their queries.
Here is a simplified explanation of the process about search engine works:
Crawling:
The search engine starts by sending out automated programs called spiders or crawlers to browse the web. These crawlers follow links from one web page to another, gathering information about the content on each page they visit. They discover new pages and revisit existing ones to look for changes.
Crawling,
in the context of the internet, refers to the process by which search engines
discover and index web pages. It involves software programs called web
crawlers, spiders, or bots, which systematically browse the web, following
links from one page to another and gathering information about each page they
encounter. Here's a simplified diagram illustrating the crawling process:
In this diagram:
The web crawler starts by sending a request to a web server
for a specific web page.
The web server responds with the HTML content of the
requested page.
The web crawler extracts links from the HTML content of the
page.
The extracted links are added to a frontier, which is a
queue or list of URLs to be crawled.
The web crawler selects a URL from the frontier and sends a
request to the corresponding web server.
Steps 2-5 are repeated for each URL in the frontier until
there are no more URLs left to crawl or until a predefined limit is reached.
This process allows search engines to systematically
discover and index web pages across the internet, enabling users to find
relevant information when conducting searches.
Indexing:
Once the crawlers gather information, the search engine indexes the content of each web page. Indexing involves analyzing the page's content, including text, images, videos, and other media, and storing this information in a massive database. This process allows the search engine to quickly retrieve relevant pages when a user enters a search query.
Indexing,
in the context of search engines, refers to the process of storing and
organizing the information collected during the crawling phase. Once web pages
are crawled, the search engine analyzes their content and creates an index,
which is essentially a structured database containing information about the
pages and the keywords they contain.
Here's a simplified diagram illustrating
the indexing process:
In
this diagram:
The web crawler collects information from web pages during
the crawling process.
The collected data is sent to the indexing engine.
The indexing engine analyzes the data and structures it into
an index.
The index is a structured database containing information
about the content of web pages, such as keywords, titles, meta descriptions,
and URLs.
The index allows the search engine to quickly retrieve
relevant pages in response to user queries.
The indexing process enables search engines to efficiently
retrieve and present relevant search results to users based on the content of
web pages and the keywords they contain.
Ranking:
When a user performs a search, the search engine retrieves relevant pages from its index based on the query terms. The search engine then ranks these pages based on various factors, including relevance, authority, and user experience. Pages that are deemed more relevant and trustworthy are typically ranked higher in the search results.
Ranking refers to the process of arranging items or entities in a particular order based on certain criteria or attributes. This can be applied to various contexts such as search engine results, sports competitions, academic performance, and more.
Here's an example of ranking using a simple
scenario:
Let's say you have a list of students and you want to rank them based on their exam scores.
|
Student Name |
Exam Score |
|
Aslam |
90 |
|
Babar |
85 |
|
Zafar |
95 |
|
Danish |
88 |
|
Akram |
92 |
In this example, the students are ranked based on their exam scores from highest to lowest:
Zafar (95)
Akram (92)
Aslam (90)
Danish (88)
Babar (85)
This ranking indicates that Zafar scored the highest (ranked 1st), followed by Akram, Aslam, Danish, and finally Babar.
Another Simple Example:
Let's consider a drawing competition where participants are ranked based on their artistic skills. Here are the rankings:
Saim
Babar
Jawad
Kamran
Rashid
In this scenario, Saim is ranked 1st, Babar 2nd, Jawad 3rd, Kamran 4th, and Rashid 5th based on the quality of their drawings.
Ranking provides a clear hierarchy and helps in understanding the relative performance or quality of items within a set.
Displaying Results:
Finally, the search engine displays the ranked position or results to the user. Typically, the most relevant and authoritative pages appear at the top of the search results page, while less relevant pages are displayed further down. Users can then click on the search results to visit the corresponding web pages.
Behind the scenes, search engines use complex algorithms to determine relevance and ranking, taking into account factors such as keywords, backlinks, user engagement metrics, and more. These algorithms are constantly updated and refined to improve the accuracy and quality of search results.
