In this chapter, we looked at the nature of the Elasticsearch index and reviewed the basic concepts: what dynamic mapping is, what it means, flexibility in the index, and what the inverted index is.

In the next chapter, you'll learn about the basic mapping concept: what basic mapping is, what the relationship between mapping and relevant search results is, Is the claim about 'Elasticsearch stands for the schema-free model' always true?, and some other subjects related to this topic.