A CSV file, or Comma-Separated Values file, is a simple text format used to store tabular data. Each line in the file represents a row, and the values in that row are separated by commas. This format is widely used for data exchange because it is easy to read and write for both humans and machines. CSV files can be opened and edited using various software applications, including Microsoft Excel and Google Sheets. They are commonly used for importing and exporting data between different programs, making it easier to share information across platforms.