EMZ is a file extension for a compressed graphics file used by the Microsoft Office Suite and Visio. Stands for Enhanced Metafile-Zipped. Contains an EMF (Enhanced MetaFile) image file that has been compressed using GZIP compression.
DXF, Drawing Interchange Format, or Drawing Exchange Format, is a tagged data representation of AutoCAD drawing file. Each element in the file has a prefix integer number called a group code. This group code actually represents the element that follows and indicates the meaning of a data element for a given object type. DXF makes it possible to represent almost all user-specified information in a drawing file.