borgbackup is a configurable script for Borg backup system. It's based on a script from official Borg documentation (https://borgbackup.readthedocs.io/en/stable/quickstart.html) but more flexible. It checks if backup repo exists and create it otherwise. Do backup with borg and clean up before exit. It gets parameters from environment variables. So, usually you don't want to run it directly. Use next script instead:
borgbackup-tohost gets username@host as an argument, set some environment variables and run borgbackup script with sudo (you need sudo to access ALL files). Edit it for your system, especially BORG_LOCAL_INCLUDES and BORG_LOCAL_EXCLUDES.