Installing Qt 5.6: Which components should I choose?

Question

I'm planning to start learning Qt (I have no previous knowledge) so I've downloaded the latest stable web installer for Windows and Linux (I've got to machines), following the directions of the Windows's wizard I got to the "Select Components" step but I'm very confused about what is everything and what do I really need.

As a newbie and with a very basic Knowledge of Qt my plan is to test my code on Windows and Linux for both Desktop Console Software and Desktop Graphics Interface Software, AFAIK I need to build my code with a cross-platform compiler like G++ which runs on Windows and Linux, so I think that is why Qt offers the installation of MinGW, but looking in the list of available components of the installer I can not fully understand which MinGW version should I choose, this is the list for Qt 5.6 installer:

There are two options for MinGW 4.9.2, Could you help to understand what is the difference? I must install both?

Another question I got is: What is the most preferred way to create UI Software using current version of Qt, Qt Widgets or Qt Quick?

Answer 1

Top one, in "Qt" section, is a distribution of Qt framework: header files and libraries compiled with MinGW GCC 4.9.2.

Bottom one, in "Tools" section is a compiler toolchain: MinGW GCC version 4.9.2.

You need both.

Be warned: GDB frontend in QtCreator has significant performance issues, especially concerning startup time. It is not very responsive as well. This makes me really uncomfortable during debugging sessions. For example, fetching values of variables may take a second or two. You will not have this problem with Microsoft toolchain. It also doesn't happen on Linux.

Also, Qt for MinGW has only a 32-bit official distribution. So you cannot build 64-bit programs with that. You will need another toolchain and to build Qt distribution from source code yourself (or to get it from 3rd party source).

_{You may use Visual Studio on Windows and GCC on Linux. It usually works fine, as Qt hides most of the platform and compiler specifics. An advantage is that these compilers, standard libraries, runtimes and debuggers are drastically different: you get double strength of compiler warnings, heap memory diagnostics and code portability. Just make sure you compile on both platforms time to time. You may even have multiple toolchains and Qt distibutions installed on Windows and check against all of them. You can set-up your projects and switch between toolchains in two clicks. You can add and remove them any time. Experiment! Don't be afraid to break it. ;)
P.S. geek mode enabled: 20 Gb of full happiness}

Regarding Qt vs QtQuick there is only one answer for that: it depends. Also it is offtopic on StackOverflow to ask that. You might take a look at these answers. I strongly encourage you to try both.