In which directory are service configs and systemd unit files stored in Linux?

Configuration files for systemd services and unit files are usually stored in several main directories:

• /etc/systemd/system/ — contains user and local unit files, which have priority over system files. Custom services are typically placed here.
• /lib/systemd/system/ or /usr/lib/systemd/system/ — system unit files installed by the distribution packages.
• /run/systemd/system/ — temporary unit files that can be created during system operation.

For configuring specific services, additional files in directories like /etc/systemd/system/<service>.d/ are often used to override settings without modifying the original unit file.

Example of viewing a service's unit file:

cat /etc/systemd/system/nginx.service