Before saying what search engine optimization (SEO) is, you want to redraw this phrase a little bit. Notice that there are two meaningful parts inside this phrase. One is the search engine and the other is optimization. Now you might want to know what the search engine or optimization is? Search engine is a program such as Google Bing, Yahoo or Yandex that searches the Internet for keywords given to users. Optimization is a process that helps in making something more perfect and effective. It means SEO is a technical web strategy to optimize the search engine, which helps to bring a website to the best position or to the first page of search results. Now the question is how do we actually optimize. The question is too small, but the answer is quite large. So, I will not go into full discussion on this issue right now.
You have come to know that the search engine has links to thousands of thousands of information, and links to relevant web pages, in contrast to your written phrase. Now the question is how is the search engine doing this job. They basically complete this task at three stages. First of all, information about billions of web pages is collected through crawling; Secondly, by analyzing the collected data, it keeps the huge database in the form of index; And finally, it gives you a list of results by comparing the phrase in your search bar with its database. This whole process is accomplished by using search engine optimization and algorithm. However, the interesting thing is that search engines have been working crawling and indexing as long as preparing to list the results of your search.