Get Form Key (Vs) Get Rendered Task Form

Hi there,

Could anyone please explain to me what is the difference between the following 2 REST API calls ?

What I want to achieve is to get (retrieve) an html form (filled in with its values) like the following one from Tasklist:

Thank you in advance,
Steve

In case of the 2nd rest call (for the rendered task form), does anyone know please if the rendered form content includes also the filled in value fields ?

Thanks,
Steven