Why compressed directories cannot be extracted in /opt?

I am not able to uncompress a file with .tar.gz extension

Did sudo tar -xvzf ~/Downloads/file.tar.gz /opt/ but no success. it says:

tar: /opt: Not found in archive
tar: Exiting with failure status due to previous errors

You can specify in which directory you want the files extracted using the -C option. Change your command to:

sudo tar -xvzf ~/Downloads/file.tar.gz -C /opt/

Your are telling tar to look for /opt/ inside the tar file and to extract only that and since it is not in that tar file it throws an error. Do:

cd /opt
sudo cp  ~/Downloads/file.tar.gz .
sudo tar -xvzf file.tar.gz

use --directory before the directory path at which you would like to extract:

sudo tar -xvzf ~/Downloads/file.tar.gz --directory /opt/