Design Web Format (DWF) represents 2D/3D drawing in compressed format for viewing, reviewing, or printing design files. It contains graphics and text as part of design data and reduces the size of the file due to its compressed format. The reduced file size makes the distribution and communication of rich design data efficient. DWF doesn't require the recipient to know about the usage of CAD software that created the original drawing.
A file with .emz extension is a compressed container of Enhanced Metafile (.emf file). It follows GZIP compression algorithm and takes less storage space due to compression. The small file size makes it more easy to transfer EMZ files over the network.
You can also convert DWF into many other file formats. Please see the complete list below.