Tbh, if you don’t know what that means, you can’t trust it.
Though, it means that unless it’s running locally on your own hardware and not in the cloud and you haven’t verified the source code directly (or someone else you trust hasn’t) then assume it is nefarious and do not give it any personal or sensitive information you wouldn’t want anyone on the Internet to know.
Name, address, phone number, Bank info, nude photos of yourself, etc. If the info being released could harm you or in some way negatively impact your life, assume it would be sent to China or anywhere else on the world wide web if you ran it without following the previous guidelines.