Microsoft Excel 1997-2003 is the name of the file type created by four different releases of Microsoft Excel. The release of Microsoft Excel 97 was a major leap forward in terms of functionality and usability compared to the previous version, Excel 95. Excel 2000, Excel XP and Excel 2003 all followed featuring tweaks to the appearance and functionality however the core application remained consistent. It was during this period that computers became incredibly popular for both personal and business use resulting in Excel becoming the de facto spreadsheet application. Excel provided functionality to a basic user with a requirement to store data in an organised fashion up to advanced users requiring formulas, charts and pivot tables.
Microsoft Excel 97-2003 used XLS as the file extension. This was a binary file format. Later versions of Excel make use of a XML for file formats. Excel 2003 limits the user to a maximum of 65,000 rows per worksheet and a maximum of 256 columns. By comparison, later versions of Excel provide support for over one million rows and 16,000 columns. Excel 2003 features a 256 colour palette limit whereas later versions allow for unlimited colours.
PDF is a file format developed by Adobe Systems for representing documents in a manner that is separate from the original operating system, application or hardware from where it was originally created. A PDF file can be any length, contain any number of fonts and images and is designed to enable the creation and transfer of printer-ready output.
Each PDF file encapsulates a complete description of a 2D document (and, with the advent of Acrobat 3D, embedded 3D documents) that includes the text, fonts, images and 2D vector graphics that compose the document. They do not encode information that is specific to the application software, hardware, or operating system used to create or view the document.