Document Input — One input of this document when another document uses it as a block: the value that document sets, by this block's name.
Document Output — One output of this document when another document uses it as a block: what arrives at Value, of any kind, which that document reads by this block's name (as block.Name).
Samples — The sample points of a study, for the document this block uses: a Table with one column per number Document Input of that document, named like the Input, and one row per sample.
Study — A parameter study of the document this block uses: the document computed once per row of a Table whose columns are named like its Document Inputs, each row's values set on those Inputs (an Input without a column keeps its default).