Key Concepts: Index, Document, Field, Query

The words we use

You send documents to an Opensolr Index. A search asks the index a question and gets the best matching documents back.

What goes in, where it lives, what comes out.

Opensolr Index: The place where your searchable data lives, usually one per website or app. Solr calls it a core or a collection. Each index runs in one region and has its own documents, configuration, disk space and monthly bandwidth.
Document: One record in the index: a web page, a product, a PDF page, an article. Search results are documents.
Field: One named value of a document, such as its title, text, price or date.
Schema and configuration: The files that say which fields exist and how text is searched, such as schema.xml and synonyms.txt. The configuration files.
Query: A search request. Opensolr finds the matching documents and returns them best match first.
Region: Where an index runs: a server location and a Solr version, chosen when the index is created. Regions.
Cluster: One index kept on several servers, a master and its replicas, so searches keep working if one server fails. Clusters and replicas.
Plan limits: Your plan sets how many indexes you can have, and the disk space and monthly bandwidth of each one. Disk space, Bandwidth.