I just want to know, what is the difference between ubuntu Minimal, Desktop & Server Editions? How they differ? is it by performance? If yes which one is recommended for a normal user and which one is recommended for a advanced user ?
The difference comes from the kernel and software installed.
They only differ from the installed packages, which you can later easily modify. If you want to install a server, choose the server version, if you want to use it as a desktop, choose the desktop version. If you need more performance, compile your own kernel from source. Btw: if you want a lowlatency kernel in precise (this is a new thing) you can install the package. Your system will be more responsive but the cpu usage will be higher.