Both formats store the same underlying data; the difference is shape. CSV is flat -- rows and columns, one value per cell. JSON is nested -- a record can contain arrays and objects inside other objects.

Use CSV when the audience is a person opening a spreadsheet, or when every record genuinely has the same flat set of fields with no one-to-many relationships. A list of business names and addresses is naturally flat -- CSV is the right call.

Use JSON when records have nested or variable structure: a product with multiple variants, an article with tags and related links, a dataset template with a fields array of unknown length. Forcing that into CSV means flattening it into awkward repeated columns or splitting it into multiple files.

Most dataset products on this site ship in both: JSON as the canonical, structurally complete version, CSV and XLSX as flattened exports for spreadsheet users. That covers both audiences without picking a side.