What is an index file and why does it matter in modern computing?

What this post added

This post provides a foundational explanation of index files, their mechanics (B-trees, hash tables), and their application in various systems including search engines. It details the advantages and disadvantages of indexing and contrasts index files with data files. For Meilisearch, it highlights how the engine builds lightweight, high-performance indexes supporting advanced search features like search-as-you-type, typo tolerance, filtering, and rapid updates, enabling developers to achieve better relevance and speed without custom indexing systems.