Search engines are online tools that allow users to find information on the Internet by entering queries ( keywords or phrases) using a search form.
Search engines help Internet users find useful and relevant results in response to their query and provide a quality user experience.
The most popular search engines are:
Search engines use complex algorithms to rank web pages in their search results. The algorithms consider factors such as relevance, authority, and quality of the pages to rank them. Search results may include links to web pages, images, videos, news, and other types of content.
Search engines generally work by following these steps:
Search engines send robots ("crawlers" or "spiders") to explore the Internet, as soon as they find a new page they analyze it and capture the resources (pages, documents, music, images, videos...) from all the hyperlinks found on the page.
The robot in this step takes a copy of content every time it visits a new page or updated page and stores it in the search engine servers. The robot extracts the keywords from each page and reports them in the web directory called Index.
After indexing, the servers perform a ranking of all web content referenced in the index in order of relevance according to many specific criteria:
Search engines use an algorithm that suggests the most relevant and useful documents for the keywords entered in the query.
A spell checkerthat corrects errors in the keywords entered by the user.
An anti-dictionarythat removes all non-significant words "the", "the"...
A lemmatizerthat summarizes the searched sentences with the most relevant words.
Users can refine their searches by using advanced search operators, such as: