How to make content indexed for further search on it?

Question

PHP

Good day.
Recently I read an article on Habré about how to make a search in php taking into account morphology. And there was a point about creating an indexing of the site content, in order to search for this table, and not for the articles themselves.
It was also said that using LIKEit is not a good idea if there are a lot of articles or products. That it loads the server.
I would like to understand the general principles of how to do such an indexing? Is it necessary to iterate over each word of the product, discard unnecessary prepositions, conjunctions and write it into the index table and assign each line a product ID?
I know that there is Sphinx and ElasticSearch, but I would like to figure out how it all works, for the purpose of self-education, so to speak :)

Answer 1

The main structure in almost all (99%) modern search engines is an inverted index