32-bit and 64-bit OS
Recently I installed Ubuntu on my stationary computer. The CPU is a 64-bit thing and the Ubuntu I am used to is a 32-bit edition. So what would be the difference?
First off.. I was not noticing any differences. Everything is the same, anyway so it looks. One major reason to use the 64-bit edition is the possibility to use all 4 GB of memory that my computer has. I have been running Windows XP 32-bit edition on this computer since i got it 6-7 months ago. But 32-bit edition is limited to only use 3.2 of the memory(not sure about the exact number). Thus the full capacity of 4 GB was not used, which I, of course would like it to be. Then the last two months I have been trying out Windows Vista 64-bit edition. It runs perfectly.. except for a random BSOD(blue screen of death, a Microsoft phenomenon which crashes your pc 
) now and then, caused by my graphic cards driver. In windows 64-bit you can install and run both 32-bit programs and 64-bit programs, without noticing any difference.
So I tried to install skype on my Ubuntu 8.10 64-bit edition. Downloaded it from the skype.com site and tried to install the package but was surprised that I got an error telling me that the architecture of my machine did not match the package I had just downloaded. I was surprised because I have been used to not care about the architecture of the applications I install when using windows. I did a quick search to find the proper package from the skype.com site but it wasn’t available. Too bad, I had to find another solution.
Since I already knew that skype is part of the medibuntu repository I added that to my sources list. Then I tryed to install skype from the terminal, the usual and easy way it works:
sudo apt-get install skype
And the skype was installed, pretty easy actually.. but confusing that you cannot find the right package from the skype site.
As for why this trick worked out the issue I don’t know. My guess would be that the ubuntu crew has compiled the packeges for both architectures. Perhaps I will figure this another time .
Here is an article from the ubuntu help community that explains something about the different architectures https://help.ubuntu.com/community/32bit_and_64bit.