dmg The .dmg extension file is a disk image file, formatted by Apple Macintosh OS X. These files are usually used to install programs on computers having Mac OS. These files cannot be opened easily on Windows Operating Systems as they are intended for use on Macintosh Operating Systems.
txz The TXZ file extension is typically found in archive files which are created using a combination of TAR and the XZ utilities. TXZ files contain multiple files which are first archived using Tar and later compressed using the technology of XZ compression. TXZ files are known to be smaller in comparison to TGZ files. From a more basic perspective, XZ utilities compress TAR archive files just like how GZ utilities compress various TAR archives, the only difference being in the compression ratios and the resulting file sizes after compression.