RHEL v7: how to make tgz file

How to make a tgz file and backup

cd /
tar -cvzf /root/file.tar /usr/local
ls -al /root/file.tar

gzip /root/file.tar
mv /root/file.tar.gz /root/file.tgz
ls -al /root/file.tgz

gunzip /root/file.tgz
ls -al /root/file.tar