XLSX
XLSX is the modern Microsoft Excel spreadsheet format — an XML-based workbook inside a ZIP container. It holds formulas, multiple sheets, charts, and formatting, and opens in Excel, Google Sheets, and LibreOffice Calc. Convert XLSX to PDF when you need to share a spreadsheet that looks identical everywhere and cannot be accidentally edited.
PDF
PDF (Portable Document Format) freezes a document’s exact layout so it looks identical on every device. It is the contract, invoice, eBook, and academic-paper format of record. PDFs can hold text, vector graphics, raster images, forms, and digital signatures — but editing them outside specialized tools is painful, which is why PDF-to-Word is one of the most-searched conversions.