It's easy and simple as the keywords are being searched on the search bar and the searching algorithm works at the back end giving you search results in microseconds. SEO is getting your website ranked higher in the search bar when any related keyword is typed your website should be accessed first by the users.
How to use SEO effectively?
It requires the keywords to be smartly inserted in the abstract and title of your webpage. Using the keywords right and at the right places is the jist of SEO. Optimizing the words so that the search results get the information you want and almost right. Google has advanced with providing search results for almost everything like people, places, reviews, e-commerce, literature, General Awareness, news etc. Search algorithms are altered for each every kind of search.
Popularity and links
Linking the sites to the required pages, videos, and websites can help you get your page ranked higher as you have all the information connected and one does not have to type the keyword again and again in the search box.
Crawling prevention is done by not allowing certain undesirable content for this the webmaster make the spiders not to crawl the undesired pages. Robot.txt is used to instruct the spider from the history of the user as to which pages are not t be crawled.