Hi @marcel_szimonisz ,

Yes, whether the check box is checked or unchecked, the files are getting processed sequentially in alphabetical order.
But few advantage of enabling the check box and making it as a loop (as above image) are,
- If there are multiple files in the directory, the file collector will fetch all the files together and once it gets picked up, it will move all the files to storage directory. And incase if there is any error in the workflow next to file collector, again we have to place all the files in the directory and rerun the workflow. But when having the loop concept, only one file will get moved to storage directory (if the workflow fails), and we can fix the Workflow and place that particular one file again and rerun the workflow.
- If keep interim of the workflow is enabled, We can able to monitor the performance and results of each file's data sequentially.