The init system is the first program to start when a computer boots. Its role is to start other program automatically and to let you manage them more easily. The recommended option for Windows is Task Scheduler.
How to know which init system I have?
You can use this little script.
if [[ `systemctl` =~ -\.mount ]]; then echo "SystemD"; elif [[ -f /etc/init.d/cron && ! -h /etc/init.d/cron ]]; then echo using "SysVInit"; else echo "Can't tell"; fi