My file request files are named with "inbound" and a number

I have noticed that in my file request folder, there are several files named with a pattern such as inbound 116653248292738278 (as an example). I would appreciate it if you could help clarify the following:

• What does the "inbound" designation signify in this context?
• Is there a specific meaning or identifier associated with the sequence of numbers following "inbound"?

Understanding this would help me manage the folder more effectively and ensure that all files are processed correctly.