So I am having trouble understanding how people make distributions how was slackware made how was redhat and the others made? Are they coding in UNIX and the oneswho make Redhat based distributions are they recoding the UNIX or are they just making C++ files to edit the way it works. Wow I am confused....

They found this nice operating system and tons of cute apps. All for free!
They collect them, make decisions on what to put into the new distro (depending what the goal of the distro is and their personal taste).
Then they eventually write some scripts and apps to make the whole work together smoothly.

At least, that's how I think it goes, but I don't have a clue really.;-)

Further to what estiedi said, the way I see it is:

A distribution is a collection of normally precompiled packages of a lot of different software, comming with an installer helping you set up which packages end up on your system as well as helping you set up your hardware. Some really focus on selecting packages (e.g. slackware) while some seem to do everything for you (e.g. mandrake)

Some distros do modify the source code, especially of the kernel (e.g. gentoo), but for the most part, the packages are decided by the creators and the community who use them.

But I ain't complaining, if we had to do LFS everytime we reinstalled it'd be a hastle, thank god for Patrick @ slackware.org, he's maintained a good distro for a very long period of time (over 10 years!)

Steve