Search Engines Explained In Basic Terms
A search engine, such as Google and Yahoo, are tools that allow users to find information on the World Wide Web by searching with a specially designed tool. The results of a search are organized into a list which includes web pages, information about them and links to them. In some cases, it includes images. Search engines are operated algorithmically in conjunction with human editing.
The search engines stores millions of pages of data available on the web and then uses different processes to deliver the most relevant data required by the users. Web crawling, indexing and searching are different processes that are used for the purpose and the order remains the same. The web crawler which is also known as the web spider works by scanning all the visible links. The web crawler, working as an automated web browser, examines all the pages and takes a decision on the indexing of the pages.
Descriptions and meta tags are analyzed to determine the type of webpage and its purpose. The meta tags are behind the scenes in the webpage and the viewer never sees them while browsing the page. The search engine uses them as a quick scan to get the idea or theme of the page and then the entire contents of the webpage will be evaluated to ensure the tags are correct and the page is valid.
Companies such as Google store all or part of the source web page, while AltaVista stores every page word for word. The information stored and indexed is known as the cache, it allows for instant updating and keeps the searching filtered with ease. An important factor for a successful search engine is its ability to provide active and useable information with minimal to no linkrot. The cache also saves an archive of a removed source that can later be access by the user after the site is updated.
Search engine users normally input a keyword or key phrase into the search field. The engine will search for their particular keyword and key phrase on the World Wide Web. The search engine index will provide an organized list of results with the best matched web pages. A short summary of each webpage describing the contents is provided along with the list.
All the search engines look to enhance their performance by ensuring that they deliver exactly what the user looks for. The problem is accentuated by the abundance of web pages containing the keyword or the keyword phrase. However, by using web crawlers and indexing, search engines manage to filter all the sites that are irrelevant to the search being made even if it has the keywords. They have created their own unique processes for examining different web pages and their contents.
Page rank is latest addition in the techniques used by search engines to sort out various web pages and their contents. Page rank decides the relevance of a particular page by studying the correlation between its meta tags, descriptions, keywords used and the content of that webpage. The search engines rank those sites high that have association with high ranked web pages. The page rank is essential for any web page or site as it determines its probability of featuring at the top of any particular search.
