DGN files are drawings created by and supported by CAD applications such as MicroStation and Intergraph Interactive Graphics Design System. It is used for creating and saving designs for construction projects such as highways, bridges, and buildings. The format is similar to Autodesk’s DWG file format and is considered its competitor.
XLAM files are used to extend the modules provided by Excel. They can be added to Excel 2007 or later, or to earlier versions of Excel with Open XML component support. File used by Microsoft Excel, a program that allows users to create and edit spreadsheets; contains a macro-enabled add-in, which provides extra functionality and tools that may execute macros.
You can also convert DGN into many other file formats. Please see the complete list below.