I have been studying and working in the SEO field for a couple of years, not too long but not too short. In other industries, having two or three years of experience only makes you a novice. But when I think about when the SEO industry actually emerged, and look at many peers who are even newer to the field, I realize that I am actually considered somewhat of an old hand. After doing SEO for these few years, if I carefully reflect on the work I do every day, I often get confused: what exactly is SEO? There are a lot of forums and blogs sharing related techniques and experiences, but if you really think about it, none of these techniques are unique to SEO, or rather, there isn't really a single thing called SEO.