Finances lets you export your transactions as a CSV or report file.
Export as CSV file, if you want to transfer transactions to financing or spreadsheet apps (e.g. Numbers or Excel). Exporting as CSV file may cause loss of information, because Finances is based on double-entry bookkeeping and a CSV file is based on single-entry bookkeeping. Therefore a CSV file is not a proper backup – see backup.
Export as report, if you want to get a detailed overview over your transactions for every account. A report is exported as a PDF or HTML file.