gtk+-2.0
libgtk-3-0 - compiled files, in this case pre-installed libgtk-3-0-dev - headers so you can link to the compiled libraries, usually not pre-installed gtk+3.0
libgtk-3-0 - compiled files, in this case pre-installed libgtk-3-0-dev - headers so you can link to the compiled libraries, usually not pre-installed gtk+3.0