You see this question almost everywhere and see bunch of different answers. Well, I’ll try to make it as simple as possible. Here is what search engine optimization is for my opinion:
Everybody prefers simple stuff. That’s why when we need to learn about something, we go to Google or Bing or any other search engine because they tell us best answers (at least try to tell us best answers) so we don’t need to do bunch of research for whatever it is. Then, it is easy for us to choose any link at the first page because who the hell going to go through all those pages (maybe million results and thousands pages…).
So if you are not at the first page of that search result, it means you won’t get anything 99.99% (I know it is a little better than that but any way). That’s what search engine optimization is. Race to be at the first page so you can get some visitors to your website.
So what should you do for it? Google says they look for hundreds factors to rank websites and no one know what they are. Plus they make hundreds of changes to their search algorithm every year. Therefore search engine optimization specialists are similar to lawyers. They need to read every updates, study all possibilities, do a lot of researches and so on and yes they do charge a lot like lawyers.
So you can do it by yourself or you can hire someone to do it for you or (the best one) be yourself and create something that first you love it (if you love it, others will follow you). Probably at the end, you won’t need any of search engines.