This progress window is opened by the dialog "Fetch Documents" and is used to display the progress in retrieving documents from a certain source.
A line that indicates the URL of the document and the HTTP status code of the response is printed to the progress window for each retrieved document. Thereafter, the document is parsed for further references to other documents, if designated for this.
The time elapsed during the process and the number of retrieved documents is presented in the final summary.
The operation can be terminated prematurely without corrupting any file that is involved in the process. But note that it may be impossible to re-start the operation later, especially in case when retrieved documents are saved to files on the local filesystem (see also section "Restrictions" of the dialog).