A tar.gz file and a .tgz file are similar.
Compress files using tar:
tar -cvzf <name of tarball>.tgz /path/to/source/folder
for example, I want to create a backup.tgz or backup.tar.gz from folder /home/user/project
tar -cvzf backup.tgz /home/user/project
tar -cvzf backup.tar.gz /home/user/project
You can use tar cvzf instead of tar -cvzf as well.
Extract .tgz or .tar.gz files using tar
tar -xvzf backup.tgz
tar -xvzf backup.tar.gz
Mnemonic for compression (the order of the flags do not matter)
C ompress
Z ee
F ile
V erbose
Mnemonic for extraction (the order of the flags do not matter)
e X tract
Z ee
F ile
V erbose