Can someone please explain the variable values in the attached example

regarding a simple single form text input, there always seems to be 2, 3 and sometimes 4 value options. How do I identify which to choose in a workflow when sending that inputs value to the backend?

task input - value is the older version, probably still there for backwards compatibility.
Formdata and fields is the newest, where formdata can be used to send all values to backend (Sending the whole formdata) and fields is there to aid with form validation. Both formData and fields can be used equally.

Its documented here: Form container | Documentation

If you are new to weweb the docs is a valuable source of information: https://docs.weweb.io/

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