A CSV (comma-separated values) file is a plain-text format for storing tabular data. Each line typically represents a row, with fields separated by commas; quotation marks may be used when a field contains commas or line breaks. CSV files can be opened by spreadsheets, databases, and scripts.
In cyber security, CSV files may contain sensitive records, credentials, or other exported data, so their contents and access controls matter. Attackers may steal or leak CSV exports, while defenders inspect them during investigations and handle them carefully to avoid exposing data. Treat a CSV file as data, not as inherently safe: spreadsheet applications can interpret specially crafted cells as formulas, and files may include secrets that require secure storage or removal.