CSV (Comma-Separated Values) is a simple text format where fields are separated by commas and records are separated by newlines. It is widely used for data exchange between spreadsheet applications and databases.

The CSV specification is defined in RFC 4180, but in practice there are dialect variations across software. Fields containing commas or newlines must be enclosed in double quotes, and double quotes themselves require escaping. Data analysis introduction books cover CSV handling techniques.

In Japanese environments, character encoding issues are common. When opening CSV files in Excel, UTF-8 files without BOM may display garbled characters, requiring Shift_JIS or BOM-prefixed UTF-8 output.

From a character count perspective, CSV delimiters like commas and quotation marks affect data size. For large datasets, CSV tends to have less overhead compared to JSON. Excel data management books provide additional context.