Priority level of a config file. These priority levels correspond to the natural escalation logic (from higher to lower) when searching for config entries in git.git.
git_config_open_default() and git_repository_config() honor those priority levels as well.
System-wide configuration file; /etc/gitconfig on Linux systems
XDG compatible configuration file; typically ~/.config/git/config
User-specific configuration file (also called Global configuration file); typically ~/.gitconfig
Repository specific configuration file; $WORK_DIR/.git/config on non-bare repos
Application specific configuration file; freely defined by applications
Represents the highest level available config file (i.e. the most specific config file available that actually is loaded)