A program that searches and identifies entries in a database that match user-specified keywords or characters, specifically used to find specific web pages on the google search engine ranking works.
Search Engines Google, Yahoo, Bing, etc.
Search Engine Indexes:
A search engine index is a database of keywords and website correlations so that search engines can display web pages that match a user’s search query.
For example, if a user searches for cheetah running speed, the software crawler will look for those terms in the search engine’s index.
Search Engine Spider (also known as a crawler, Robot, SearchBot, or simply Bot) is a program that most search engines use to find new information on the Internet. Google’s crawler is called GoogleBot. The program starts on a web page and tracks every hyperlink on each page.
Therefore, it can be said that everything on the web will eventually be found and analyzed, because the so-called “spider” crawls from one site to another. When a web crawler visits one of your pages, it loads that page’s content into its database.
Once a page has been fetched, your page text is loaded into the search engine’s index, which is a huge database of words and where that appear on different web pages.
Web crawlers crawl some websites without approval. As a result, every web page includes a robots.txt file that contains instructions to the spider (web crawler) about which parts of the site to index and which to ignore.
As the web crawler crawls each site, it follows all the links on the site and checks the number of links connected to each site. And then it assigns a percentage to each site that represents the importance of the site using the page ranking algorithm. For example, if there are three sites named A, B, and C. Suppose the number of links connecting to B is from five sites with less percentage and site C with links from A with percentages.
Page Rank in a URL graph is a probability distribution used to represent the probability that a random person clicking on links will arrive at a particular page.
So there are basically three steps involved in the web crawling the web process. First, Google search Engines crawlers start by crawling the pages of your site. It then continues to index the words and content of the website, and eventually, it hits the links (website address or URL) on your website.
The importance of “robots.txt”
The first thing a spider has to do when it lands on your site is looking for a file named “robots.txt”. This file contains instructions for crawlers about which parts of the site should be indexed and which should be ignored. The only way to control what a spider sees on your site is to use the robots.txt file.
All crawlers are subject to certain rules, and most of the major search engines follow these rules. Fortunately, major google search engines like yahoo or Bing have finally worked together on standards.
- How many times does the page contain this keyword?
- Do words appear in the title, in the URL, or adjacent?
- Does the page contain synonyms for these words?
- Is this page a quality or poor-quality site?
And then it fetches hundreds of web pages and ranks the importance of those sites using the PageRank algorithm to see how many external links point to it and how important those are. Finally, it combines all of these factors to generate an overall score for each page and returns search results about half a second after the search is submitted.
Each page includes a title, URL, and text to decide what specific page we’re looking for. And if it’s not relevant, it also shows related searches at the bottom of the page.
How Google Search Works
It happens billions of times a day in the blink of an eye and we can have anything our minds can think of!
Let’s explore the art and science of making this possible. Crawling the web and indexing:
The journey of a query begins before we even enter a search, with crawling the web and indexing trillions of documents.
Google uses software called Web Crawler to explore publicly available web pages. The most famous crawler is called Googlebot. The crawler looks at the web pages and follows the links on those pages and goes from link to link and brings the data on those web pages back to Google’s servers.
The Web is like an ever-expanding public library with billions of books. Basically, Google crawls the pages in the crawl and then creates an index like the one at the end of a book. The Google index includes information about words and their positions. When we search, at the most basic level, their algorithms search our search terms in the index to find relevant pages.
Algorithms are computer processes and formulas that receive and solve our queries from thousands of web pages with useful information. Google search engines uses the PageRank algorithm developed by founders Sergey Brin and Larry Page. Today, Google’s algorithms rely on over 200 unique signals, including our site terms, content freshness, and region, that help guess what we’re looking for.
Google Search Engines Anti-spam:
Spam sites try to get to the top of search results through techniques like repeating keywords over and over, buying links that pass PageRank, or displaying invisible text on the screen. This is not good for search because relevant sites are buried, and it is not good for legitimate website owners because their sites become harder to find. The good news is that Google’s algorithms can detect the majority of spam and downgrade it automatically.