Individual mode produces a set number of records per document. It’s the mode for "one each" – one certificate, one letter, one invoice per record – and the default for most jobs.
Each output document contains a set number of records, one by default. Run it over 200 records and you get 200 documents – or fewer files if you group several records into each.
When you want more than one record per document – say four labels in a file – you set a Set Size. That’s next.
Group several records per document: Set Size