Files with IFC extension refer to Industry Foundation Classes (IFC) file format that establishes international standards to import and export building objects and their properties. This file format provides interoperability between different software applications. Specifications for this file format are developed and maintained by buildingSMART International as its Data Standard.
XLSX is well-known format for Microsoft Excel documents that was introduced by Microsoft with the release of Microsoft Office 2007. Based on structure organized according to the Open Packaging Conventions as outlined in Part 2 of the OOXML standard ECMA-376, the new format is a zip package that contains a number of XML files. The underlying structure and files can be examined by simply unzipping the .xlsx file.
You can also convert IFC into many other file formats. Please see the complete list below.