A TGZ file is a compressed archive created using GZIP, an open-source data compression program. It is commonly used among UNIX and Linux users for combining several files to make them easier to share and transport. TGZ files are based on the gzip file format, which is used for encryption and compression. They can contain larger files than the resulting file thanks to file compression. TGZ files can also be split up into multiple files that can be combined, making it easier to transfer large files without risking file loss.

To open a TGZ file on Windows, there are several options. One way is to use 7-Zip, a free and open-source file archiver. Another option is to use WinRAR, a popular compression file utility. To extract the contents of a TGZ file using 7-Zip, you can right-click the file in File Explorer and select "Open Archive" or "Extract files" to choose a file location. To extract the contents of a TGZ file using WinRAR, you can double-click the file and choose the files you want to extract/open, then click on the "Extract To" icon at the top of the WinRAR window.

Its worth noting that TGZ files are used as install packages for some Linux distributions, and therefore the ".tar.gz" extension is sometimes used for archives while the ".tgz" extension is used for installers.