What does Full-text search engine mean?

A full-text search engine is a tool that searches the entire text content of documents, web pages or databases for occurrences of the entered words or phrases. Unlike searching only by title or predefined fields, it works with the content as a whole. Typical examples are internet search engines, which index the content of web pages and then show users results that match their query. Full-text search is also used directly in e-shops, where it helps customers find products by name, description, parameters or other text information. The quality of the results depends, among other things, on how indexing and relevance evaluation work.