An input is a resource that is needed within a step. An input can be included from a preceding step, it can also be imported from a group that is enclosing the step, or created as a new resource in the step itself.
Below, the "Seed Inoculum" from an enclosing group is assigned as an input to the "Cell Culture" step.
"Incubator Shaker" is not imported into the "Cell Culture" step from a preceding step; it is imported directly from the resource library.
The "Wash Cells" step takes a "cell culture" from the previous "Cell Culture" step as an input. The "1x PBS" and "Operator" are imported directly from the resource library.