git tree?

Hi all,
just got a 2440 3.5" board. My aim is to compile a u-boot image, a kernel
image and a root file system to be flashed in my board.

whereevr i look for a process to compile all these(u-boot kernel) i get git
trees and all.I'm new to linux.
-Can anyone tell me what is a git tree?? 
-Cant i compile my U-boot and Kernel without the git.like if i download the
source or something??.
-I guess git needs good internet speed. i have a slow internet link. 
-What about file system?

Thanks,
Rose

1. Google for a better explanation then I could give.
2. Yes, you could get the source from kernel.org.  However, it may not be
up to date go to: 

http://repo.or.cz/w/linux-2.6/mini2440.git

and get something that most likely works.

Think one of the neat things about git is that next time you go to get
something newer you only download things that have changed.  A real help
with that slow link!
4. Make your own?  Go to:

http://blog.leshak.ru/english/pages/how-to-install-u-boot-linux-2629-roo...

I have written a tutorial on my experiences trying to make a rootfs.jffs2
over the last month.  If you want more reading material I'll figure out how
to attach it here after changing it to a .pdf

Good luck!