file_field

At: Ruby on Rails - File Uploading

You can find:

<%= file_field 'upload', 'datafile' %>

I saw the file_field documentation from here:

But, still cannot get how the parameters 'upload' and 'datafile' work.

Based on the documentation:

upload ---> object_name datafile ---> method

How is that?

Can you clarify on this?

Thanks.