Has SEO Service changed over the years?

How long has SEO been around? Quite some time now, since 1995 some or the other form of search engine optimization was around. So, has SEO changed? Is it still the same? Well, to get straight to the point, SEO has changed. Reason being – search engines have evolved over time and the ability to determine the most appropriate search result has become more accurate. SEO service has also changed since.