QT creator and Qt ( just itself) difference - Starting QT

I'm asking for a good re-confirmation! (don't take it otherwise).. As I'm quite new in the Qt platform, I've found it quite confusing!! In Windows platform, you've: Qt 5.4.1 for Windows 32-bit (VS 2012, OpenGL) which is a whooping 644 MB file! & also the info about "Qt Creator" in download says:

Blockquote Qt Creator 3.3.1 is included in the Qt 5.4.1 binary packages. If you need a standalone installer, please select the file according to your operating system from the list below to get the latest Qt Creator for your computer

--- this a layman would understand as Qt Creator is the GUI of Qt IDE & also you need to download "Qt 5.4.1 for Windows" which is a whooping 644MB !! so, WAIT FOR A MOMENT...

Blockquote is this the case? or I've to download just the Qt Creator for my work?