Ubuntu Packages: Binary Compilation
I am a tyro to Linux and have just installed Ubuntu 11.10 on my machine for few days. I have some questions about Ubuntu packages. As I am going to install QT Creator IDE in an offline way --just to get more acquainted to Linux binary codes compilation-- I load this <packages.ubuntu.com/oneiric/devel/qtcreator> page. My questions are:
1. I know that I must basically download the green diamonds. But what about red circles (or blue squares)? Should I get them? In case I use Ubuntu Software Center and install say, QT Creator which items of the <packages.ubuntu.com/oneiric/devel/qtcreator> page are installed automatically?
2. How can I compile these binary codes? I googled but most of results concern online installation which isn't my case.