I'm not sure exactly what you mean, but in the beginning Yahoo's search engine was based on actual humans organizing things by semantic terms.
As the number of websites grew into a riotous horde, this approach became impracticable. Eventually the big G won out with robots searching
for new sites and algorithms to look for "relevant" search terms.
The problem is that the quantitative can be gamed. So you do a search and you get several thousand very similar websites, all of which have lifted
their information from some original website that you can't find because the thousand sites have applied SEO techniques to boost their quantitative
assessment and the original site did not. If you visit those sites, you will get a chiding note admonishing you how the web will collapse if you keep
using an ad-blocker. They don't mention that it's their manipulations that make it impossible for you to find the actual source site that may deserve
your support.