Depending on the step that is selected within the workflow designer canvas, properties or inputs for the step are rendered as shown on the graphic. As you can see from the graphic, each step has meta data such as name and descriptions; fyi- name is a required field. The condition to evaluate input requires an expression to evaluate, another required field.
"More Info" also opens up a section to provide logging and documentation for the step, these are optional fields. As said before, depending on the step, these inputs and controls displayed for the inputs can vary.
Once the step properties are configured and the "Save" button is clicked, properties are saved and automatic step input validation is performed. If a step has any custom validation built in, custom validation is also performed.