A search engine is a software which is used to search for any particular information on the web. While the search engine does not produce any information by itself, it searches for the information one is looking for, through the World Wide Web and presents a list of results that contain the information. The search takes place by running an algorithm and is not done manually. It makes this software much more efficient.
The results are often presented as a list of web pages, photos or videos with the link of the parent website. The highest ranked web page according to the search engine appears at the top of the list of results. The web pages are ranked by the search engines according to their relevance to the users. It happens without any payment from the web page to the search engine and is entirely dependent on the merit of the web page. Such results are referred to as organic, natural, editorial or earned results. If a web page appears at the top or if it appears frequently, more visitors tend to visit the page due to its visibility.
While there are many search engines (example: Google, Microsoft Bing, Yahoo, Ask.com, Baidu etc), it is no surprise that Google is the ultimate word in this field and can be considered as a synonym to ‘Search Engine’. So much that at times SEO simply refers to Google optimization.
Various processes affect the visibility of a web page in the unpaid section of the results. These methods are collectively called Search Engine Optimization (SEO). Simply put, SEO is the process or practice that increases the visibility of a web page or website in the organic results to generate traffic from search engines. While there are many search engines available today, it is no surprise that Google is the ultimate word in this field. So, often SEO simply refers to Google optimization.
Search Engine Result Pages (SERPs)
As the name suggests, SERP is quite simply the results of the lists of results produced by the search engine when a searcher initiates a search. Apart from the direct results of a keyword search the search engine also displays advertisements. As was discussed above, the results are either organic – entirely based on the merit of the web page or they are advertisements where the web page has paid Google to display their page at the top.