Web Deploy - If you have IIS on a server running and configured to receive Web Deploy requests, it will send all files requested by IIS. IIS will immediately start running the new page.
Web Deploy Package - If you have IIS on your server running and configured to receive Web Deploy Packages, it will package your entire web page and upload it to the server. IIS will immediately start running the new page.
FTP will upload all files to the FTP server (this can be any OS that can handle FTP), but be aware that this is NOT secure and the entire upload process can be captured and compromised.
File System will send all the files required to launch the web service, by any method supported by the current project, to the directory you provide on your machine.
Summarizing:
Web Deploy - If you have IIS on a server running and configured to receive Web Deploy requests, it will send all files requested by IIS. IIS will immediately start running the new page.
Web Deploy Package - If you have IIS on your server running and configured to receive Web Deploy Packages, it will package your entire web page and upload it to the server. IIS will immediately start running the new page.
FTP will upload all files to the FTP server (this can be any OS that can handle FTP), but be aware that this is NOT secure and the entire upload process can be captured and compromised.
File System will send all the files required to launch the web service, by any method supported by the current project, to the directory you provide on your machine.
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