As a regular Ubuntu user I am used to using apt for system maintenance. But now that I've installed Arch Linux I will be using pacman and so below is a cheat sheet for myself that shows the pacman equivalent of some common apt actions.

Action Apt Pacman
Install a package apt install pacman -S
Remove a package apt remove pacman -Rs
Search for a package apt serch pacman -Ss
Upgrade packages apt update && apt upgrade pacman -Syu
Upgrade distribution apt update && apt dist-upgrade pacman -Syu
Clean up local caches apt autoclean pacman -Scc
Remove unused dependencies apt autoremove pacman -Qmq | pacman -Rs -

Install a Package

$ pacman --sync <package name>

$ pacman -S <package name>

Installs a package and its dependencies.

Remove a Package

$ pacman --remove --recursive <package name>

$ pacman -Rs <package name>

Removes a package and all its dependencies, provided that (A) they are not required by other packages; and (B) they were not explicitly installed by the user.

Search For a Package

$ pacman --sync --search <regexp>

$ pacman -Ss <regexp>

Searches in the sync database for packages with a name or description that match the regexp.

Upgrade Packages

$ pacman --sync --refresh --sysupgrade

$ pacman -Syu

Downloads a fresh copy of the master package database and then upgrades all out-of-date packages.

Upgrade Distribution

$ pacman --sync --refresh --sysupgrade

$ pacman -Syu

Since Arch uses a rolling release system there is no distribution version as you just upgrade your packages to their latest versions.

Clean Up Local Caches

$ pacman --sync --clean --clean

$ pacman -Scc

Free up disk space by removing from the cache any packages that are no longer installed. Also removes any cached sync databases.

Remove Used Dependencies

$ pacman --query --deps --unrequired --quiet | pacman --remove --recursive -

$ pacman -Qdtq | pacman -Rs -

Remove dependencies that are no longer needed, because e.g. the package which needed the dependencies was removed.