Difference between xxx.service and xxx@user.service in systemd

[Chris Green]

I am a bit confused by systemd user services.

I have two service files in ~/.config/systemd/user/ as follows:-

    -rw-rw-r-- 1 chris chris 184 Jan 29 18:14 fblcd@chris.service
    -rw-rw-r-- 1 chris chris 178 Jan 27 21:32 helmlcd.service

They are very similar, helmlcd.service is:-

    [Unit]
    Description=Run the helm display

    [Service]
    Type=simple
    StandardOutput=journal
    ExecStart=/home/chris/bin/helmlcd.py
    Restart=on-failure

    [Install]
    WantedBy=default.target

The differences in fblcd@chris.service are just the description and
the executable file:-

    [Unit]
    Description=Run the Flying Bridge display

    [Service]
    Type=simple
    StandardOutput=journal
    ExecStart=/home/chris/bin/fblcd.py
    Restart=on-failure

    [Install]
    WantedBy=default.target


Both are installed and run (using systemctl) in the same way, so
what's the difference between them?  What does the @chris do, if
anything?

These are both written by me so they may very likely be misconfigured
in some way. :-)  They are running on a headless system and I want
them to run when the system is [re]booted.  They run continuously
displaying electrical values on two LCD displays.

-- 
Chris Green
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