Why some distros 700mb (CD) and some 4gb (DVD) ?

I know with 4gb dvd iso files you can install more software from dvd.

But the 4.3gb-700mb= 3600mb (approximately) space is only about with software setups?

Or is there any less libraries?

For example why's the size difference between ubuntu (700mb) and suse (4gb)?

This is a bit of a useless question isn't it?
Why so lazy? Got nothing better to do?
No wonder you got no replies, the answer's obvious - all you need to do is look inside the CD and the DVD to find out.
Please do not post these questions any more, they are useless and give this Web site a bad name by raising the number of 'no-reply' questions.

I agree with Slack1_more

Simplicity v. comprehensive options/flexibility? 1 Ubuntu cd installs the OS, a graphical environment, and a set of applications chosen by the developers. I don't know exactly what's on the Suse dvd, but it's probably similar to the Slackware dvd I have- the OS, several optional GUIs, and multiple options regarding apps- several text editors, a couple of web browsers, etc.(3 cds worth right there). The Slackware dvd also includes, among other things, the sources for everything on the disc(another 2-3(?) cds). That adds up to slightly less than 4gb; I'm sure other install dvds are similar in content.

Since it's not a no-reply question any more anyway... as I understand it, a "distro" consists of Linux itself, plus as many useful freely available programs as will fit on the distribution device, usually a CD or DVD. Although there's no rule to say the disc must be full. But you can also get - can buy - a distro on a USB memory stick. That is, you buy a memory stick and Linux is already on it. However, your Linux may be able to copy itself from CD to stick anyway - Knoppix 6.0.1 can. (Although apparently the copy can't copy itself, so since I'm planning to do that tonight, I'll need to get the CD out again. I put Knoppix onto an SD card, but now I want to use the card for something else.)

CD and DVD also come in different capacities, specifically 8 cm diameter discs. Since they operate by recording a single spiral line of data from the hub to the edge of the disc, on the smaller discs with the same design, the space runs out sooner, that's all. Oh, and the disc type is encoded somewhere, so that I wasn't able to install a CD ISO onto a DVD, the PC insisted it was the wrong kind of disc. Maybe there's a way to force it.

Sorry

If I'd know I get a reply something like yours, I'd never post this question in my head and bother myself to learn "what are the differences".

There's a saying in my own language, if I translate it to english it would say: not knowing is not a shame. the shame is "not trying to know".

In most distributions there is far more available content than would fit on a DVD. Whoever makes the DVD or CD is guessing which content will be desired by a large fraction of those using the distribution. After you get that content from the CD or DVD, you can get the rest by downloading individual packages over the net.

A CD is far more than enough for a minimal distribution that gives you enough of Linux to use it to get the rest of what you want over the net.

I also don't understand the point of a distribution that doesn't fit on one CD, especially not the Centos distribution.

If you will use a distribution multiple times (which I certainly do with each Centos version) the download overhead of getting a much bigger initial distribution might trade off well vs. having every install go out to the net to pull in all the extra pieces. That benefit is greatly reduced by the fact that the distribution designer can't guess exactly which subset of packages you will want. But maybe the benefit could still exist despite that reduction.

Except that in Centos (maybe I've done something wrong every time) toward the end of the install it goes out to the net, not the DVD, for all the optional packages you have selected and for lots of updates to all the standard packages (even when that version of Centos was newly released). So the installer takes a DVD and a very long .iso download then gets so much from the net during install that it doesn't beat the smallest bootstrap type installers. Luckily I have good network bandwidth at the site where I have done multiple Centos installs, but the DVD still seems to be a waste.

For liveCD use, a DVD would make more sense. Getting extra packages over the net once per boot is a lot more lame than once per install. So the benefits of DVD over CD for that are clearly greater and worth the bigger .iso download. So why is the Centos liveCD just one CD, while the Centos installer is a choice of multiple CDs or one DVD?

I would think it would depend on what you wanted out of a liveCD/DVD...I don't need or want to use a live disc instead of an installed OS- my only real use for one would be as a rescue disc, so a small one would be fine. I've used the 1st Slackware disc and a Slax CD to fix systems I've messed up a couple times.
I agree that a DVD would make more sense if you wanted more apps, or just more choices, and wanted to do more than just fix things on the HD.

That's exactly my point!
You did NOT try to know, you didn't even bother to download the two and look at their contents.
Posting a question here should be a last resort after you have had a go at finding the answer for yourself.
Lazyness is never excusable, in ANY language.

Let's not argue okay?

But I've downloaded, installed, tried, and also googled "why linux distros 700mb 4gb" or something like that. I didn't looked into the CDs but if I looked I still couldn't have understood clearly. I just saw the "software selection" menus at installation but they cannot be 3600mb.

That's why I asked. That's what I want to know.

I hope you consider the possibility of some of us maybe isn't experienced at linux as you are.

Why not?

I don't know what distribution you are talking about so I don't know what "software selection menus" you mean. But I've seen software selection menus in Linux that offer far more than 4GB of software. (Take the extreme example of Synaptic in any Debian based distribution).

As I said above, I'm also unclear on what the DVD is accomplishing in a Centos install. The optional software selection menu during install might represent nearly 4GB (though I would guess it is less). But, unless I did it wrong, that optional software ends up downloading from the net rather than installing from the DVD. Once Centos is installed, you can use Yum to select from far more than 4GB of software, but that also comes from the net.

I expect some DVD distributions (maybe Centos if I hadn't made some as yet unidentified mistake) do what you would expect and have over 3GB of optional packages that can be installed from the DVD instead of installing optional packages from the net.

The other install I've done enough times to remember well is Mepis from CD. IIUC, you don't have install time choices of optional packages. During install you get everything from the CD. Then you can add or remove things later by running Synaptic. Unless you are absurdly short of disk space, I think that install work flow is more convenient than asking extra questions during the install.

OK, this is my final posting on this, I really didn't expect you to be so defensive of such an obviously at-fault position.
You say "I've downloaded, installed, tried".
Well the NEXT thing is to look at what you downloaded, or go to the original site and look around.

As I say I have no wish to prolong this so here is my final word.
I happen to be a Slackware user in Australia, so I downloaded my last distro from:
ftp://mirror.pacific.net.au/linux/sl...ckware64-13.0/

Guess what's in there? A file called FILELIST.TXT.
Guess what's in that file?
Look for yourself: ftp://mirror.pacific.net.au/linux/sl...0/FILELIST.TXT

Oh, and by the way, the file size is the fifth column... don't say I'm not being helpful.

Now why do you think people would dare to call you lazy? Hmmm? I wonder....

Seems to me you're just trolling in this thread. Have you even considered the time needed to download these ISOs?
People like you are damaging the community.

Thanks all people who want to help, there are good information on this topic. I've now a more clear mind about what I asked.

@Slack1_more
You're too aggressive.

I have even gone to the trouble of listing URLs for this lazybones to go look at the contents.
Now if I can find it, why can't he?
Because he didn't LOOK!
It does not take a rocket scientist to do some quick searches on the Web.
That he did not find his information first means that he WAS NOT LOOKING!
He'd rather clutter up this site with mindless messages than do some work!
You wonder why I call him lazy?
BECAUSE HE IS!
AND he does NOT deserve your defense.

And YOU, unless you popped off you criticism of my effort before my last message was on-line here, are just as bad as him!