You can export a CSV file from Redshift using four different methods: the UNLOAD command, the AWS SDK, the AWS command-line interface (CLI), and a SQL client. The UNLOAD command allows you to quickly export data with simple SQL queries, while the AWS SDK provides more flexibility and customization options. The AWS CLI offers another way to execute SQL queries and download data, and a SQL client can be used to connect to Redshift and export data directly from your local machine. These methods offer varying degrees of complexity and customization, allowing you to choose the best approach for your specific use case and needs.