What is the difference between GTK# and windows forms? Are they totally different?
Thanks
In short: Yes
Both are GUI-Tookits, but WinForms (as the Name says) was mainly developed for windows. GTK has been developed for Gimp and is an approach for a multi os gui toolkit .
If your application only runs on windows, in most cases you should use WinForms.
If your application will run under different OS' (like linux, bsd, windows, macos,... ) you'll prefer GTK.
For a better explanation look here.