You may not want certain pages of your site crawled because they might not be useful to users if found in a search engine's search results. If you do want to prevent search engines from crawling your pages, Google Search Console has a friendly robots.txt generator to help you create this file. Note that if your site uses subdomains and you wish to have certain pages not crawled on a particular subdomain, you'll have to create a separate robots.txt file for that subdomain. For more information on robots.txt, we suggest this Webmaster Help Center guide on using robots.txt files13.
In 1998, two graduate students at Stanford University, Larry Page and Sergey Brin, developed "Backrub", a search engine that relied on a mathematical algorithm to rate the prominence of web pages. The number calculated by the algorithm, PageRank, is a function of the quantity and strength of inbound links.[22] PageRank estimates the likelihood that a given page will be reached by a web user who randomly surfs the web, and follows links from one page to another. In effect, this means that some links are stronger than others, as a higher PageRank page is more likely to be reached by the random web surfer.
WhatsApp was founded by Jan Koum and Brian Acton.WhatsApp joined Facebook in 2014, but continues to operate as a separate app with a laser focus on building a messaging service that works fast and reliably anywhere in the world.WhatsApp started as an alternative to SMS. Whatsapp now supports sending and receiving a variety of media including text, photos, videos, documents, and location, as well as voice calls. Whatsapp messages and calls are secured with end-to-end encryption, meaning that no third party including WhatsApp can read or listen to them. Whatsapp has a customer base of 1 billion people in over 180 countries.[46][47] It is used to send personalised promotional messages to individual customers. It has plenty of advantages over SMS that includes ability to track how Message Broadcast Performs using blue tick option in Whatsapp. It allows sending messages to Do Not Disturb(DND) customers. Whatsapp is also used to send a series of bulk messages to their targeted customers using broadcast option. Companies started using this to a large extent because it is a cost effective promotional option and quick to spread a message. Still, Whatsapp doesn't allow businesses to place ads in their app.[48]
Think about the words that a user might search for to find a piece of your content. Users who know a lot about the topic might use different keywords in their search queries than someone who is new to the topic. For example, a long-time football fan might search for [fifa], an acronym for the Fédération Internationale de Football Association, while a new fan might use a more general query like [football playoffs]. Anticipating these differences in search behavior and accounting for them while writing your content (using a good mix of keyword phrases) could produce positive results. Google Ads provides a handy Keyword Planner34 that helps you discover new keyword variations and see the approximate search volume for each keyword. Also, Google Search Console provides you with the top search queries your site appears for and the ones that led the most users to your site in the Performance Report35.

Search engine optimization consultants expanded their offerings to help businesses learn about and use the advertising opportunities offered by search engines, and new agencies focusing primarily upon marketing and advertising through search engines emerged. The term "search engine marketing" was popularized by Danny Sullivan in 2001[12] to cover the spectrum of activities involved in performing SEO, managing paid listings at the search engines, submitting sites to directories, and developing online marketing strategies for businesses, organizations, and individuals.
Optimization techniques are highly tuned to the dominant search engines in the target market. The search engines' market shares vary from market to market, as does competition. In 2003, Danny Sullivan stated that Google represented about 75% of all searches.[64] In markets outside the United States, Google's share is often larger, and Google remains the dominant search engine worldwide as of 2007.[65] As of 2006, Google had an 85–90% market share in Germany.[66] While there were hundreds of SEO firms in the US at that time, there were only about five in Germany.[66] As of June 2008, the market share of Google in the UK was close to 90% according to Hitwise.[67] That market share is achieved in a number of countries.