A CSV file is a text file used to store structured data. The CSV format is used to transfer structured data between applications or to export data in order to perform data analytics.

The first use case is data transfer. Applications such as e-commerce software, mailing list providers, or CRM deal can import and export data in the CSV format. In e-commerce software, it is common to import a CSV containing the product catalog. When managing a mailing list, importing a CSV with all the email addresses is faster than adding each contact one by one.

The second use case is data analytics. The CSV format is flat and is perfectly compatible with spreadsheet or data analytics tools. As a result, it is a good source to analyze and visualize data. A CSV file has no size limit and can contain millions or more of records. It is a good file format to use in Big Data.