apt – zlib1g: command not found

I’m trying to uncompress a zlib compressed file

ubuntu@a:~$ sudo apt-get -f install zlib1g
Reading package lists… Done
Building dependency tree
Reading state information… Done
zlib1g is already the newest version (1:1.2.8.dfsg-2ubuntu4.3).
0 upgraded, 0 newly installed, 0 to remove and 49 not upgraded.

ubuntu@a:~$ zlib1g

zlib1g: command not found

ubuntu@a:~$ zlib
No command ‘zlib’ found, did you mean:
Command ‘olib’ from package ‘geda-utils’ (universe)
Command ‘slib’ from package ‘slib’ (universe)
zlib: command not found