A search engine is a computer program that is designed specifically to perform web searches, so as to search the World Wide Web for specific information, usually with reference to a keyword or phrase. The most common search engines are Google, Yahoo!, and Bing.

In order to receive traffic from a search engine, websites need to be listed on the search engine results page, or SERP. In other words, if a user types a keyword or phrase into the search engine search box and clicks the search button, the search engine search results page will be displayed. This listing is done based on the popularity and relevance of the selected websites. Hence, high-ranking factors for websites would drive the traffic. To make sure of this, the website needs to comply with the search engine policies and procedures.

Search engine optimization or SEO is the art and science of making a website more accessible or visible to the search engines through specific techniques and methods. The process includes various activities like writing meta tags, title and description, keyword density, web coding and other important elements. Some basic steps are also involved such as submission of site to all major search engines, regular updates of site content and directory submission. To increase the visibility of the website among search engines, web developers create in-house or outsourcing SEO service. By outsourcing the SEO works, you get to concentrate on other aspects of your business.

One of the best ways of attracting traffic to a website is through search engines. One of the best ways to attract visitors to a website is through search engine optimization or SEO. SEO improves the ranking of the website in search engines result pages (SERPs). So, higher the ranking on the search engines result pages (SERPs), better is the chance of attracting the maximum number of visitors.

There are many ways to improve the ranking in SERPs. Keywords or phrase density plays an important role in increasing the rankings in SERPs. Proper HTML meta tags, inclusion of important keywords in title, keywords at the start of the web pages, inclusion of alternate texts, and inclusion of meta description and keywords throughout the content are some of the common SEO techniques used. Meta tags also provide necessary information about the site to search engines. For instance, in meta description, the key words or phrases are included in the title of the web page so that they do not have to be interpreted manually by the search engine. Inclusion of pictures and other visual elements on web pages also enhance the importance of the page.

So, we know that how the search engines work. They crawl the web and take note of the indexed websites. They collect the information and make it available for crawler or spider to work upon. Crawling has become one of the most important tasks of web developers.