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After WWW protocol was introduced in Internet in the early 1990s and the number of web servers started to grow, the first technology that appeared to be able to locate them were Internet listings, also called web directories. A web directory lists web sites by category and subcategory. Web directory entries are usually found and categorized by humans. Web directories lost their main aim when Internet Search Engines appeared and have been slowly disappearing (one of the most famous, yahoo directory, closed in December 2014). 2
A web search engine is a software system designed to search for information on the World Wide Web. Today s search engines have 3 main components A group of programs called Web Crawlers, Robots, Web-Bots or Web Spiders that navigate websites retrieving all the information from its web pages and following the links that they find to continue gathering information. This programs are constantly crawling the web, registering new pages and changes in existing ones. A central database that stores the words found, with the pages were they are located, and computes a weighted index with the relevance of each page for each word. The algorithms used are a well-kept trade secret, as the competitiveness of a search engine relies on giving more relevant search results than its competitors. The initial Google weighting index is called Google pagerank and is based on the number of incoming links and the quality of those links (determined by the number of incoming links that the linking pages have). Now it has been modified by several extra algorithms that take into account the quality of page content, whether it is original, and other factors to avoid cheating. There is a never ending race between the Search Engines trying to give genuine results and the owners of web pages trying to fool them into putting their pages in the first places. 3
A Search Interface allows the user to enter search queries, and presents the results ordered by relevance in a list called SERP (Search Engine Result Page). 3
Search engine optimization (SEO) is the process of increasing the visibility of a website or a web page in a search engine's unpaid results for specific keywords related to the business of the company. In general, the earlier a site appears in the search results list, the more visitors it will receive from the search engine's users. Depending on which type of search we are interested in, SEO may target different kinds of search, including image search, local search, video search, academic search, news search and industry-specific vertical search engines. SEO deals with how search engines rate pages for a specific keyword (something that they never disclose and that they change from time to time but people keep investigating) and with what people are looking for and how they are using the search engines to search. 4
Search engine marketing (SEM) is a form of Internet marketing that involves the promotion of websites by increasing their visibility in search engine results pages (SERPs) primarily through paid advertising (which is what gives Google most of its revenue, for example). Depending on what we consider paid advertising, SEM may incorporate search engine optimization (SEO), as adjusting or rewriting website content to achieve a higher ranking in search engine results pages at a cost (even an internal cost). The largest search engine marketing (SEM) vendors are Google AdWords, Bing Ads, and Baidu. 5
The SEO optimization process is cyclical, and starts by studying business requirements and websites, researching afterwards which keywords Internet users are using to look for the products or services the company wants to offer, writing content, optimizing websites, submitting the changes to search engines and achieving external links considered relevant for the important keywords, studying the results and starting again in a new improvement cycle. 6
If you want a keyword to rank higher in a Search Engine Result Page, you will need to work on two fronts: On page SEO, optimizing your content, making the keyword appear in the meta title of the page, in the headings of the page and in the text of the page (but not too much) and in the alt tags of the images for example, sending a sitemap to Google and taking some other actions on your site. Off page SEO, linkbuilding, that is, trying to attract links to your page from important domains, building a community in social networks, and similar actions outside of your site. And you will have to wait little bit because SEO actions take a while until they have an effect on Search Engine results. 7
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