Check out example codes for "how to make services in linux". It will help you in understanding the concepts better.

Code Example 1

[Unit]
Description=<description about this service>

[Service]
User=<user e.g. root>
WorkingDirectory=<directory_of_script e.g. /root>
ExecStart=<script which needs to be executed>
Restart=always

[Install]
WantedBy=multi-user.target

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