How to show all installed packages on Ubuntu
Similar to Debian systems, Ubuntu uses apt and dpkg to do basic package management. The Debian package manager, or dpkg, is available for the task to show all installed packages.
Using dpkg to list packages
Running the dpkg command is as simple as providing only the providing the --list option.
# dpkg --list
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name Version Architecture Description
+++-======================================-=======================================-============-================================================================================
ii adduser 3.118ubuntu5 all add and remove users and groups
ii amd64-microcode 3.20191218.1ubuntu2.2 amd64 Processor microcode firmware for AMD CPUs
ii apparmor 3.0.4-2ubuntu2.3 amd64 user-space parser utility for AppArmor
ii apport 2.20.11-0ubuntu82.5 all automatically generate crash reports for debugging
ii apport-symptoms 0.24 all symptom scripts for apport
ii apt 2.4.12 amd64 commandline package manager
ii apt-utils 2.4.12 amd64 package management related utility programs
ii base-files 12ubuntu4.6 amd64 Debian base system miscellaneous files
ii base-passwd 3.5.52build1 amd64 Debian base system master password and group files