Where are the configuration files of package managers located in Linux systems?

In Linux, configuration files for package managers are usually located in the /etc directory. For example:

• For APT (Debian, Ubuntu) — /etc/apt/ (files sources.list and folder sources.list.d for repositories)
• For YUM/DNF (CentOS, Fedora) — /etc/yum.repos.d/ (files describing repositories)
• For Pacman (Arch Linux) — /etc/pacman.conf and folder /etc/pacman.d/

Thus, the main place for configuration is subdirectories and files within /etc, specific to each package manager.