ifc to fbx conversion represents export of 3D models between Industry Foundation Classes format (.ifc) and Kaydara exchange format (.fbx), probably for 3D content from various BIM tools or models of buildings and similar.
Both formats should be well-supported in modern BIM/3D modeling software, either directly or via plugin and you can always use one of the dedicated CAD converters ad well.
Many tutorials about export/conversion of BIM content can be found on the Internet or Youtube.
Updated: October 6, 2023