When using some online tools you may find that files are provided in a GZ (gzip) or ZIP file format. These are examples of file compression, where a file is made smaller. This makes uploading and downloading files much quicker. The approach is slightly different depending upon your Operating System, so advice is given here on the major ones.
Windows
Although the capabilities to deal with ZIP files is built into Windows Vista, the best approach is to use a third party tool, 7-zip being a recommendation. Download and install this program. Once installed it integrates into Windows Explorer.
To compress a file you first need to decide the compressed format required – Zip or GZ. Then right click on the file in Windows Explorer and choose ’7-zip -> Add to archive’. Ensure that your selected format is supplied.
To decompress a file simply right click and choose on of the ’7-Zip -> Extract to …’ options as you require.
Linux/OS
GZIP (with gz file extension) can be handled by tools in the OS accessible from the command line using a tool called GZIP. At a command prompt type ‘GZIP -h’ to ensure it is available. Using the cd command go to the directory with the item in it and GZIP -d filename handles uncompressing a downloaded file.
For normal ZIP files you can use ‘zip filename‘ or ‘unzip filename‘ instead. These tools may not be present but typical installations of Linux and OSX will contain Visual Tools accessible whilst using an explorer type interface.