FTP files after transfer from server to local browser

[Al]

I was wondering if the files for a website remain active on the server after they are transferred to a local browser for editing? Does a copy of them still exist on the server for use when the website is accessed by someone? If not, then is the website compromised while these files are being edited?

[falkencreative]

If you copy files off a web server and place them on your local machine, they will still exist on the server for people to access them unless you delete the files off the server after the transfer. They will be available for others to view if they access the website.

[Al]

Thanks Ben for your reply. I assume, then, that once I've made my changes and send the updated files back to the server, the previous files will be replaced with the new ones. Is this correct? My concern, being new to this experience, is to avoid accidently deleting something by mistake. When I send the updated files back to the server, will I be prompted in some way to verify whether or not I want to replace the old files with the new ones?

[virtual]

Yes your updated files will replace the old ones when you upload them to the server if have kept the same file name. As to whether, you will be prompted to verify, this will depend on which FTP program you are using. I use DW and if will verify, I don't know about other FTP's