Hi,
Attach to Step Opens the Attachment page, enabling you to view and add attachments to the actual test steps in the Run details. (see Attach to step.png)
Attach to Run Opens the Attachment page, enabling you to view and add attachments to the test run under attachments in the Run details. (see Attach to run.png)
In run details window we can see the exact difference between Attach to Step and Attach to Run. In Run Details, Attachments Tab section, this is where an attachment added with the Attach to Run option would be stored. The Run Details, Steps Tab is where an attachment added with the Attach to Step option would be added. I have attached the screenshots(Attach to Run, Attach to Step, Attach to) to this case for more information.
![alt text][1]
ALM will not transfer that screenshot to 'Test Plan' module. I tested this in our test environment. Refer the attached screenshot (Attach to) for more
information.
[1]: /storage/temp/821-attach-to-step.png