ASP.NET Forum

http is Hypertext Transfer Protocol, used for stateless data transfer. It uses Request - Response objects to communicate between each other.

FTP is File transfer protocol used to upload / download Files. The files in FTP are directly transferred between communication channels.

FileSystem means where we store files in local hard drive.

I guess you are talking about the Location of Web Application in VS.

Http: - It will create the Virtual Directory , Directly on IIS. For that you need to configure the IIS First.

There you need to provide file path like,
http://localhost/WebApplicationname

Ftp: It will create web site on Ftp Server.

Path of your web application would be,
ftp://WebApplication

FileSystem : It will create the Web Site in your local file System, which is bydefault.
Path would be like : d:\WebApplication.

Note: For Ftp and Http you have to make sure your IIS Server Configure Properly or if you are using any Remote Server that is also configured properly