EPUB is a ebook format: it packages HTML, CSS, and images in a zipped OPS container as an ISO-standardised ebook format that reflows text to fit any screen width. CSV is a spreadsheet format that stores tabular data as plain text with one row per line and field values delimited by commas, readable by any spreadsheet or database tool. This conversion changes the file's encoding, compression method, and supported feature set. Metadata such as creation date and embedded colour profiles is preserved where the target format supports it. Converting between these two formats is common when the source application does not support CSV natively or when the target platform only accepts CSV. 1converter processes this conversion server-side using open-source tools. Files are transferred over HTTPS, converted on secure cloud servers, and automatically deleted after 24 hours.