Solr organizes data similarly to the way a SQL database does. Each record is called a 'document' and consists of fields defined by the schema: just like a row in a database table. Instead of a table, Solr calls it a 'collection' of documents. The difference is that data in Solr tends to be more loosely structured. Fields may be optional, and instead of always matching exact values, you can also enter text queries that partially match a field, just like you're searching for web
pages. You'll also see Hue refer to 'shards' - and that's just the way Solr breaks collections up to spread them around the cluster so you can search all your data in parallel.