After all the weird errors in my ubuntu system(yes, amd64) thought about putting a bare minimum system together(I'm really bandwidth cheap - 56k), after looking through gentoo and ,very briefly, LFS (bear in mind that I'm a n00b and boredline retarded) what exactly makes one incarnation of linux different from another?

Like what makes slackware not debian. If I installed portage could I emerge programs now on ubuntu? I know it's probably stupid but I cant stop wondering? Thanks for any insight.

Different flavors of Linux differ in many way. However, there are so many similarities than differences. I will try to list some of what i can think of but that's not all for sure:

1- Linux Kernel version: Different linux distros may differ in the kernel version they use. That's what makes it a linux anyway and it's the most vital part of the whole thing. Nore here that a lot of distro's share the same kernel.

2- Installation method:different linux distro differ in installation methods. Some will have live CD's, others will have GUI installation interface and others will have only plain old text install method (slackware is a good example of this one .. and Gentoo)

3- Package Management: You could compile a source code for a certain programs on all linux distros that if you met software requirements for comiling the source coe. but you can't install different binary packages on all systems without some extra work. Debian, Redhat, Slackware and others all have their own package management system. Along with a package management system comes the online installers like 'yum' and 'apt-get'

4- Desktop feel and look: linux distro's might differ in the desktop environment they run. Some come with GNOME other's with KDE and there are many other's out there.

5- Out of the box package: each linux distro is packaged differently out of the box. Some are designed to be server only systems, others for for media production others are pure desktop.

6- Support and popularity: If you buy Redhat then you get commercial support. If you go with Fedora then you don't commercial support and you will have to depend on you knowledge and community support. Ubuntu for example is widely supported for a desktop system were CentOS and Debian are very widely supported and documented as server operating systems.

That's what i can think of for now ...

Look first at the components of the typical Linux system--e.g.:
kernel
utilities--eg all the BASH commands
libraries
applications
etc.
Each component has its own development and release cycle. What the distro maintainer does is combine a set of things and tune it up so it plays together. A closely related paradigm is the package manager through which all of the dependencies are resolved. (Watch closely when installing new SW, and you see all the stuff that gets added when you install a new application.)

You CAN install things from other distros, but then you have to worry about the details of the dependencies.

The other thing that distinguishes distros is the user interface, including cosmetics, arrangement of menus, and special scripts to help manage the system.

(It's not a stupid question....)

Gone through a bit of LFS, right?

Simply put, the Distro people do a Linux from scratch, using experience from the community,
from which the noob may benefit.

90% of what makes distros different from each other is the package manager and repositories.

I'd say most of the differences are in package/software selections, other big portions being the core package manager + possible automated piece of it (like rpm + yum) and initial configurations. Slackware's initialization scripts differ from some other distributions, and different distributions might have different pre-sets for what services are enabled by default, how sshd is configured out of the box and so on.

The word "distribution" is pretty loosely defined, overall. I wouldn't make a big show about it. I take, if not defined otherwise, that a "distribution" (in this case a "Linux distribution" as they say) is an operating system that uses Linux kernel, GNU software and other software. If I need to specify it, I mention it's name (like "Ubuntu"), and that should be sufficient. If I have Ubuntu (original) and a Ubuntu-derivative that differs only by a different iconset of Gnome and a different splash image, I'm ok to say they're different distributions - if it's not ok to somebody else (being sharp about this), then it's not.

Just introduced myself to the Slackware package management system, packaging my first packages - easier than I first thought, and...awesome!

Thanks for the responses. It's the binary thing I dont get. Lets say I have slack and debian on basically the same machine and same kernel, why wont the binary run?

What do you mean by "binary"? Packages, or just single executable files? If the latter, then I don't see why it wouldn't run assuming all the required libraries were present.

Exectuable yes. So if I copied say abiword from deb to a slack and they had gnome and everything it would work?

I kinda get it now: different distro's are incompatible because theyre "configered" diferently and use different package managers?

If you copy an executable from one distribution to another, in most cases, it will work fine. The executable format is the same (ELF). One distr can have some libraries that are missing on the other one, but then, you still can install the missing library.
Some programs are even distributed as executables, blender is one example of that.

an excutable is a program that might require some system libraries to run. Every software developer put their software requirements and you have the absolute ability to install those requirements.

Why don't these libraries come pre installed from the begining? Well, that's because there are so many of them.

Additionaly, why would you want a library in your system if you're not gonna use it?

A lot of easy to use distro's come with tons of libraries and pre configured packages which makes them easier to use for desktop users.
On the other hand with some other flavors you will have the absolute choice to choose every single piece you want to install. I call that freedom

A source distro won't help you with your bandwidth problem - contrary to popular belief the packages are in most cases smaller than the source meaning you'd need to d/l more.