JARGON - pantheon-systems/search_api_pantheon GitHub Wiki

Much of the jargon used in the Solr paradigm is used elsewhere in both drupal and other technologies. Please familiarize yourself with the concept usage in a Solr context:

Commit - To make document changes permanent in the index. In the case of added documents, they would be searchable after a commit.
Core - An instance of the solr server suitable for creating zero or more indices. Solr core is a way to represent a Lucene index and a set of configurations that control the accessing and using of the index with Solr. It's the main object you will interact with when working with Solr. You will create it, configure it, indexing data in it and preform queries on it. A Solr core is a Lucene index but wrapped in Solr related configurations.
Collection - Solr Cloud's version of a "CORE". Not currently used at Pantheon.
Document - A group of fields and their values. Documents are the basic unit of data in a collection. Documents are assigned to shards using standard hashing, or by specifically assigning a shard within the document ID. Documents are versioned after each write operation. Not to be confused with a PDF document which can be uploaded to Solr and searched via the SearchAPIAttachments module.
Facet - The arrangement of search results into categories based on indexed terms.
Field - The content to be indexed/searched along with metadata defining how the content should be processed by Solr.
Index - A group of metadata entries gathered by solr into a searchable catalog.
Schema - A series of plain text and XML files that describe the data Solr will be indexing. The schema tells the server about the data that Solr will be indexing and tells solr how to return the results. Schema is generated automatically by drupal and uploaded using the PANTHEON_ADMIN tab of this module.